1 Introduction

The XBRL 2.1 specification [XBRL] defines the syntax and semantics of that syntax in order to define concepts, resources and relationships between those concepts and concepts and resources in a DTS (See section 3.2 of the XBRL Specification for a more exhaustive definition of a DTS).

XBRL has been used extensively in projects around the world. A common use of the XBRL technology has been to model an existing information supply chain between regulators and regulated entities.

The digitalization of that process, using XBRL technology, has required the creation of an XBRL taxonomy (the DTS) used by people creating XBRL reports or submitting those reports to regulators.

One of the most important benefits of XBRL technology is that XBRL is a standard about how to define the report content. This means that new reporting requirements from regulators to regulated entities can usually be incorporated using the same XBRL 2.1 technology without having to change the XBRL technology. In fact, when a new version of a DTS is released, the regulated entities will have to adapt existing mappings between internal data and the old concept definitions to the new concept definitions. It is expected that for all concepts with no significant changes the mapping rules can be adapted automatically.

On the other hand, companies preparing their financial reports using the XBRL technology can create their own taxonomies or taxonomy extensions. These companies can also make changes to his own taxonomies and may have the necessity to report to the market not only the reports according to the new DTS but also the changes they made to the taxonomies. In this case, the versioning report also serves as the communication tool in order to allow them to document the changes.

Most existing XBRL APIs are able to load the content of an XBRL DTS (a taxonomy) and can generate XBRL reports according to that taxonomy. But XBRL would not provide a true benefit at all if moving the software from one taxonomy version to another (on the report production side) or the process to review two consecutive reports from a company that has made changes to their taxonomy (on the consumers side) were a costly process for the users. This specification is specifically designed to address this issue. The reporting requirements change over time, the taxonomies change to cover those new requirements, but the technology used to create reports is the same (XBRL 2.1). Moving applications to work from one taxonomy version to the next would be a trivial operation at least for concepts whose definition is the same.

1.1 Background

A number of projects have made significant contributions to this specification. These include the IASC Foundation which has contributed a methodology on which this specification is based, and the National Taxonomy Project ("NTP") initiated by the Dutch government, which has contributed the first initial documentation of a standardisation for a Versioning report. Several other initiatives such as the Committee of European Banking Supervisors have joined efforts together in order to help the XBRL Consortium and the XBRL industry to adopt a single common solution that satisfies the most critical business requirements in all those projects.

1.2 Relationship to other work

This document pertains to XBRL as defined in the XBRL Specification [XBRL].

Parts of this document may reiterate for expository clarity certain semantic restrictions imposed by XBRL, but this document does not modify XBRL. In the event of any conflicts between this document and XBRL, XBRL prevails.

1.3 Terminology

Terminology used in XBRL frequently overlaps with terminology from other fields.

The following terms are used as described in the table below:

Term	Meaning
Arc, arcroleRef, base set, child, concept, context, duplicate item, descendant, DTS (discoverable taxonomy set), element, entity, fact, instance, item, linkbase, linkbaseRef, p‑equal, roleRef, taxonomy, taxonomy schema, u‑equal, XBRL instance.	As defined by XBRL [XBRL].
Relationship	An arc defines a relationship between its source concepts and target concepts that is determined by its xlink:arcrole and other attributes.
source [concept(s)]	The concepts identified by the URI content of the href attributes of the locator-type elements in the same extended-type link element, which have the same label attribute content as the content of the “from” attribute of an arc.
target [concept(s)]	The concepts identified by the URI content of the href attributes of the locator-type elements in the same extended-type link element, which have the same label attribute content as the content of the “to” attribute of an arc.
must, must not, required, shall, shall not, should, should not, may, optional	See [RFC2119] for definitions of these and other terms. These include, in particular: should: Conforming documents and applications are encouraged to behave as described. must: Conformant documents and consuming applications are required to behave as described; otherwise they are in error.
XBRL	Extensible Business Reporting Language (XBRL) 2.1 Recommendation [XBRL].
From DTS	The term "From DTS" is used to refer to the source DTS that is the DTS that will be compared to the "To DTS". The From DTS normally refers to the old taxonomy version.
To DTS	The term "To DTS" is used to refer to the target DTS or the DTS that is being compared with the "From DTS". The To DTS normally refers to the new taxonomy version.
Action	This specification uses the term "Action" for referring to what changes between the From DTS and the To DTS
Assignment	This specification uses the term "Assignment" for referring to the business reasons for an action to change things in a DTS or even the business reasons for starting to compare two DTSs.

1.4 Document conventions

The following highlighting is used to present normative technical material in this document:

The following formatting is used for non-normative examples in this document:

The following formatting is used for non-normative counterexamples (examples of poor, discouraged or disallowed usage) in this document:

Non-normative editorial comments are denoted as follows and removed from final recommendations:

1.5 Namespaces

This table contains all the prefixes used within the text and XPath 2.0 expressions and the correspondent namespace URI:

Prefix	Namespace URI
xml	http://www.w3.org/XML/1998/namespace
xbrli	http://www.xbrl.org/2003/instance
xs	http://www.w3.org/2001/XMLSchema
xlink	http://www.w3.org/1999/xlink
link	http://www.xbrl.org/2003/linkbase
xl	http://www.xbrl.org/2003/XLink
Error! Reference source not found.	Error! Reference source not found.

The Prefix column in the table above is non normative. The Namespace URI column is normative.

1.6 XPath

XPath expressions that appear in this document are XPath 2.0 [XPATH] expressions executed in a schema aware processor. Refer to the [XPATH] 2.0 specification for more information.

The prefixes used in the XPath expressions are indicated in section 1.5 above.

2 XBRL Versioning

Versioning is a term with several meanings. Different people have different interpretations of this term. XBRL Versioning is about standardising the content of a report of "information about the changes made to a taxonomy" in order for taxonomy users to save time in adapting their applications to a new taxonomy version.

This specification distinguishes between “technical differences” and “semantic differences”. “Technical differences” are those that can be automatically identified by software comparing the properties of the pair of information items under observation. “Semantic differences” are the interpretation of the “technical differences” made by the author of the versioning report. Given two DTSs and some rules to match information items from one DTS to the other, the set of “technical differences” is unique, but the set of “semantic differences” is unlimited because they are just an interpretation of the “technical differences”. A “semantic difference” contains an aggregation of “technical differences” and human readable documentation that may be useful input to users migrating an application from using the previous taxonomy version to the next.

For the rest of this specification the phrase From DTS will be used to refer to the DTS that is being compared with the To DTS.

For the rest of this specification the phrase To DTS will be used to refer to the DTS being compared with the From DTS.

The following figure represents the different layers in which the information of a versioning report is structured.

Figure 1: source of information for a versioning report

There are many examples that show how the information in a DTS can be written in one or many different files without any impact on applications using the DTS. A simple example:

o A taxonomy schema "A.XSD" for the namespace http://foo defining two concepts tx:One and tx:Two may reference one presentation linkbase with one parent-child arc in the http://www.xbrl.org/2003/role connecting the two concepts whereby tx:One is the parent of tx:Two.

o A different taxonomy schema "B.XSD" for the same namespace http://foo and defining the same concepts (tx:One and tx:Two), may have two embedded presentation linkbases in the same http://www.xbrl.org/2003/role role - one saying that tx:Two is the parent of tx:One and the other relationship prohibiting the previous relationship and creating another one saying that tx:One is the parent of tx:Two.

Both taxonomies are equivalent from the DTS consumer perspective because, even though taxonomy "A.XSD" and "B.XSD" are completely different in their syntaxes, both define the same concepts and the same resulting relationship between the concepts. Both DTSs define the same information set as it is used by applications consuming XBRL metadata other than, perhaps, XBRL Taxonomy editors that have more strict requirements about representing prohibited relationships to the user.

2.1 The XBRL versioning Infoset

The XBRL Infoset (Information Set) is an abstraction layer on top of the syntax layer. This abstraction layer expresses every information item in a DTS (concept definition, resource definition, relationship, etc) based on its property and not based on the syntax used to serialize it in XML Schemas or XBRL linkbases.

Versioning is built on top of the XBRL Infoset without making any reference to the actual underlying syntax. Of course, the relationship between the information item properties and the XBRL syntax exists and software tools can easily find and use it.

The XBRL versioning Infoset is a sub-set of the properties and objects defined in the XBRL Infoset. Not everything in the XBRL Infoset is related to concept definitions or resource definitions. The following table describes the set of items and properties in and out of the scope for a versioning report.

The DTS Information Item	[XIS 2.2.1]	All properties are included.
The XBRL Document Information Item	[XIS 2.2.2]	All properties are excluded[3].
The XBRL Taxonomy Information Item	[XIS 2.2.3]	Namespace [XIS 2.2.3.2] is included. All other properties are excluded.
The Imported Taxonomy Information Item	[XIS 2.2.4]	All excluded.
The Role Type Information Item	[XIS 2.2.5]	URI [XIS 2.2.5.4] is included. All other properties are excluded.
The Arcrole Type Information Item	[XIS 2.2.6]	URI [XIS 2.2.6.4] is included. All other properties are excluded.
The Used On Information Item	[XIS 2.2.7]	All properties are excluded.
The XBRL Concept Information Item	[XIS 2.2.8]	All properties are included.
The XBRL Item Information Item	[XIS 2.2.9]	All properties are included.
The XBRL Tuple Information Item	[XIS 2.2.10]	All properties are included.
The XBRL Linkbase Information Item	[XIS 2.2.11]	All properties are excluded.
The Extended Link Information Item	[XIS 2.2.12]	The role URI on extended links is used to define the relationship identifier.
The Documentation Information Item	[XIS 2.2.13]	All properties are excluded.
The Relationship Information Item	[XIS 2.2.14]	Only relationships that exist after prohibition and overriding rules defined in the XBRL 2.1 specification are considered part of a concept definition. For those relationships, only the following properties are included: Type [XIS 2.2.14.2] From [XIS 2.2.14.3] To [XIS 2.2.14.4] Arcrole URI [XIS 2.2.6.4] Order [XIS 2.2.14.6] Priority [XIS 2.2.14.8] Attributes [XIS 2.2.14.9]
The Resource Information item	[XIS 2.2.15]	All resources in the DTS are considered. See section 2.4.3 below for more information. For resources, the following properties are included: Type [XIS 2.2.15.2] Role URI [XIS 2.2.5.4] Element [XIS 2.2.15.4] From [XIS 2.2.15.5] To [XIS 2.2.15.6] Attributes [XIS 2.2.15.7] Value [XIS 2.2.15.8]

Changes to other properties that are not included in the list above can be documented in the versioning report despite the fact that they will not produce Diff Events [Def 1] according to this specification. The content model of the versioning report allows a report to contain specific documentation about a particular change and generic documentation not related to a particular change.

This specification defines the following additional properties that are derived from information that exists in the XBRL Information Set but not explicitly indicated as properties in the XIS documentation.

2.1.1

Preceding

The Preceding property of an XBRL Relationship Information Item R is the set of XBRL Relationship Information Items RS that satisfies the following conditions:

1. R and RS belong to the same Extended Link role [4], and

2. R and RS have the same value in the type property [XIS 2.2.14.2], and

3. RS is positioned immediately before R in the set of relationships that satisfies conditions 1 and 2 ordered using the value of the order property [XIS 2.2.14.6].

2.1.2

Following

The Following Relationship of an XBRL Relationship Information Item R is the set of XBRL Relationship Information Items RS that satisfies the following conditions:

1. R and RS belong to the same Extended Link role4, and

2. R and RS have the same value in the type property [XIS 2.2.14.2], and

3. RS is positioned immediately after R in the set of relationships that satisfies conditions 1 and 2 ordered using the value of the order property [XIS 2.2.14.6].

2.2 The differences between two DTSs

This specification defines the equivalency operation between two DTSs, the From DTS and the To DTS. The equivalency operation is independent of the syntax and modularization strategy used to serialize a DTS.

Two DTSs (From DTS and To DTS) are equivalent if there are no differences in the concept definitions and no differences in the resources defined in the DTSs.

Comparison of two DTSs that are not equivalent produces a set of technical differences that are identified in this specification. This specification does not pertain to define one specific algorithm to find the differences.

[Def 1] A Difference Event is the representation of something not equivalent found between properties of two corresponding XBRL Information Items being compared. This is equivalent to a “technical difference” as defined earlier in this document.

There are Difference Events defined for each type of “technical difference” that is possible between two XBRL Information Items covered by this specification.

The computation of the Difference Events requires two tables of paired properties that define the mapping rules between DTSs. See section 3.10 below and the definitions of namespace pair [Def 5] and role URI pair [Def 6]. Some properties must be compared after applying the appropriate mapping. This specification explicitly defines in which situation the mapping rules must be applied.

Some of the “technical differences” between two concept definitions or resource definitions can only be represented using a set of correlated difference events. This is for example the case of changes in attributes of a relationship that requires the following set of events:

[EvConceptRelationshipFrom] event with two parameters Error! Reference source not found. pointing to the From and To concepts. This event will be the starting event and the parent of,

[EvRelationshipAttribute] event with parameters Error! Reference source not found. pointing to the From and To relationships where an attribute has been changed. This event will be the parent of,

[EvAttributesInequality] event with parameters Error! Reference source not found. pointing to the From and To attribute whose values are not equal. This one will be the Ending event in the path.

[Def 2] A Difference Path is a set of Difference Events. Some of the events contain parameters to identify the concepts, relationships, resources, attributes or XML fragments.

[Def 3] The Starting Event of a path is always the first event in the path.

[Def 4] The Ending Event of a path is always the last event in the path.

A Difference Path contains just one starting event and one ending event. It is possible that the path contains just one event that plays the role of starting and ending event simultaneously. A Difference Path is not a tree with one starting event and multiple ending events.

The set of possible ending events is enumerated in section 2.5 below.

The set of possible starting events are those defined in sections 2.2.1, 2.2.2, 2.2.3 or 2.2.5 below.

2.2.1 Comparing two DTS Information Items:

Two DTS Information Items [XIS 2.2.1] D1 (the From DTS) and D2 (the To DTS) are equivalent if both the following conditions are satisfied and none of the “NOT equivalent” conditions below exist:

1. For each XBRL Concept Information Item [XIS 2.2.8] defined in the Concepts property [XIS 2.2.1.2] of D1 there exists a corresponding XBRL Concept Information item [XIS 2.2.8] in D2; both items are equivalent if they satisfy all conditions in section 2.2.2 or 2.2.3 below.

2. For each XBRL Resource Information Item [XIS 2.2.15] defined in the Resources property [XIS 2.2.1.3] of D1 where a corresponding XBRL Resource Information Item [XIS 2.2.15] is found in D2; both items are equivalent if they satisfy all conditions in section 2.2.5 below.

Two DTS Information Items [XIS 2.2.1] D1 (the From DTS) and D2 (the To DTS) are NOT equivalent if any of the following conditions exist:

1. For any XBRL Concept Information Item [XIS 2.2.8] defined in the Concepts property [XIS 2.2.1.2] of D1 there does not exist any corresponding XBRL Concept Information item [XIS 2.2.8] in D2,. Processors MUST document all such differences by generating a Concept deleted event [EvConceptDelete] with the concept identifier Error! Reference source not found. in the [from DTS] parameter.

2. For any XBRL Concept Information Item [XIS 2.2.8] defined in the Concepts property [XIS 2.2.1.2] of D2 a corresponding XBRL Concept Information item [XIS 2.2.8] cannot be found in D1. Processors MUST document all such differences by generating a Concept added event [EvConceptNew] with the concept identifier Error! Reference source not found. in the [to DTS] parameter.

3. For any XBRL Resource Information Item [XIS 2.2.15] defined in the Resources property [XIS 2.2.1.3] of D1 a corresponding XBRL Resource Information Item [XIS 2.2.15] cannot be found in D2. Processors MUST document all such differences generating a Resource deleted event [EvResourceDelete] with the resource identifier Error! Reference source not found. in the [from DTS] parameter.

4. For any XBRL Resource Information Item [XIS 2.2.15] defined in the Resources property [XIS 2.2.1.3] of D2 a corresponding XBRL Resource Information Item [XIS 2.2.15] cannot be found in D1. Processors MUST document any such differences generating a Resource added event [EvResourceNew] with the resource identifier Error! Reference source not found. in the [to DTS] parameter.

2.2.2 Comparing two XBRL Item Information Items:

Two XBRL Item Information Items [XIS 2.2.9] I1, which belongs to the From DTS, and I2, which belongs to the To DTS, are equivalent if all the following conditions are satisfied and none of the “NOT equivalent” conditions below exist:

1. If the value of the Namespace property [XIS 2.2.3.2] of the XBRL Taxonomy Information Item [XIS 2.2.3] referenced in the Parent property [XIS 2.2.8.1] of I1 is equal to the value of the namespace pair [Def 5] of the Namespace property [XIS 2.2.3.2] of the XBRL Taxonomy Information Item [XIS 2.2.3] referenced in the Parent property [XIS 2.2.8.1] of I2 this condition is satisfied. Processors MUST raise a Concept namespace event [EvConceptNamespace] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2. If the value of the Name property [XIS 2.2.8.2] of I1 is equal to the value of the Name property [XIS 2.2.8.2] of I2 this condition is satisfied. Processors MUST raise a Concept name event [EvConceptName] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

3. If the content of the Type property [XIS 2.2.8.3] of I1 is equivalent to the content of the Type property [XIS 2.2.8.3] of I2 according to section 2.2.8 below this condition is satisfied. Processors MUST raise a Concept Type event [EvConceptType] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

4. If the value of the Substitution Group property [XIS 2.2.8.4] of I1 is equal to the value of the Substitution Group property [XIS 2.2.8.4] of I2 this condition is satisfied. Processors MUST raise a Concept Substitution Group event [EvSubstitutionGroup] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

5. If the value of the Period Type property [XIS 2.2.9.2] of I1 is equal to the value of the Period Type property [XIS 2.2.9.2] of I2 this condition is satisfied. Processors MUST raise a Concept Period Type event [EvPeriodType] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

6. If the value of the Balance property [XIS 2.2.9.3] of I1 is equal to the value of the Balance property [XIS 2.2.9.3] of I2 this condition is satisfied. Processors MUST raise a Concept Balance event [EvBalance] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

7. If the value of the Default property [XIS 2.2.9.4] of I1 is equal to the value of the Default property [XIS 2.2.9.4] of I2. If this condition is satisfied. Processors MUST raise a Concept Default event [EvDefault] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

8. If the value of the Nillable property [XIS 2.2.8.5] of I1 is equal to the value of the Nillable property [XIS 2.2.8.5] of I2 this condition is satisfied. Processors MUST raise a Concept Nillable event [EvNillable] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

9. If the value of the Abstract property [XIS 2.2.8.6] of I1 is equal to the value of the Abstract property [XIS 2.2.8.6] of I2 this condition is satisfied. Processors MUST raise a Concept Abstract event [EvAbstract] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

10. If the value of the Block property [XIS 2.2.8.7] of I1 is equal to the value of the Block property [XIS 2.2.8.7] of I2 this condition is satisfied. Processors MUST raise a Concept Block event [EvBlock] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

11. If the value of the Fixed property [XIS 2.2.8.8] of I1 is equal to the value of the Fixed property [XIS 2.2.8.8] of I2 this condition is satisfied. Processors MUST raise a Concept Fixed event [EvFixed] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

12. If the value of the Final property [XIS 2.2.8.9] of I1 is equal to the value of the Final property [XIS 2.2.8.9] of I2 this condition is satisfied. Processors MUST raise a Concept Final event [EvFinal] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

13. For each XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of I1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of I2 exist; both relationships are equivalent if they satisfy all conditions in section 2.2.4 below. Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 below.

14. For each XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of I1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of I2 exists; both relationships are equivalent if they satisfy all conditions in section 2.2.4 below. Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 below.

15. For each XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of I1 where a corresponding XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of I2 exists; both attributes are equivalent if they satisfy all conditions in section 2.2.7 below. Processors MUST raise a Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.7 below.

16. For each XML Element Information Item in the Children property [XIS 2.2.8.13] of I1 where a corresponding XML Element Information Item in the Children property [XIS 2.2.8.13] of I2 exists; both XML Elements are equivalent if they satisfy all conditions in section 2.2.6 below. Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.6 below.

Two XBRL Item Information Items [XIS 2.2.9] I1, which belongs to the From DTS, and I2, which belongs to the To DTS, are NOT equivalent if any of the following conditions exist:

1. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of I1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.8.10] of I2. In this case, Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

2. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of I2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.8.10] of I1. In this case, Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] with the relationship identifier Error! Reference source not found. in the [To DTS] parameter.

3. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of I1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.8.11] of I2. In this case, Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

4. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of I2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.8.11] of I1. In this case, Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] with the relationship identifier Error! Reference source not found. in the [To DTS] parameter.

5. For any XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of I1 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.8.12] of I2. In this case, Processors MUST raise a Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters followed by an Attribute deleted event [EvAttributeDelete] with the attribute identifier Error! Reference source not found. in the [From DTS] parameter.

6. For any XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of I2 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.8.14] of I1. In this case, Processors MUST raise a Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters followed by an Attribute added event [EvAttributeNew] with the attribute identifier Error! Reference source not found. in the [To DTS] parameter.

7. For any XML Element Information Item in the Children property [XIS 2.2.8.13] of I1 a corresponding XML Element Information Item cannot be found in the Children property [XIS 2.2.8.13] of I2. In this case, Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters followed by a Element node deleted event [EvNodeDeleted] with the XML element identifier Error! Reference source not found. in the [From DTS] parameter.

8. For any XML Element Information Item in the Children property [XIS 2.2.8.13] of I2 a corresponding XML Element Information Item cannot be found in the Children property [XIS 2.2.8.13] of I1. In this case, Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters followed by a Element node added event [EvNodeNew] with the XML element identifier Error! Reference source not found. in the [To DTS] parameter.

2.2.3 Comparing two XBRL Tuple Information Items:

Two XBRL Tuple Information Items [XIS 2.2.10] T1, which belongs to the From DTS, and T2, which belongs to the To DTS, are equivalent if all the following conditions are satisfied and none of the “NOT equivalent” conditions below exist.

1. If the value of the Namespace property [XIS 2.2.3.2] of the XBRL Taxonomy Information Item [XIS 2.2.3] referenced in the Parent property [XIS 2.2.8.1] of T1 is equal to the value of the namespace pair [Def 5] of the Namespace property [XIS 2.2.3.2] of the XBRL Taxonomy Information Item [XIS 2.2.3] referenced in the Parent property [XIS 2.2.8.1] of T2 this condition is satisfied. Processors MUST raise a Concept namespace event [EvConceptNamespace] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2. If the value of the Name property [XIS 2.2.8.2] of T1 is equal to the value of the Name property [XIS 2.2.8.2] of T2 this condition is satisfied. Processors MUST raise a Concept name event [EvConceptName] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

3. If the content of the Type property [XIS 2.2.8.3] of T1 is equivalent to the content of the Type property [XIS 2.2.8.3] of T2 according to section 2.2.8 below this condition is satisfied. Processors MUST raise a Concept Type event [EvConceptType] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

4. If the value of the Substitution Group property [XIS 2.2.8.4] of T1 is equal to the value of the Substitution Group property [XIS 2.2.8.4] of T2 this condition is satisfied. Processors MUST raise a Concept Substitution Group event [EvSubstitutionGroup] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

5. If the value of the Nillable property [XIS 2.2.8.5] of T1 is equal to the value of the Nillable property [XIS 2.2.8.5] of T2 this condition is satisfied. Processors MUST raise a Concept Nillable event [EvNillable] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

6. If the value of the Abstract property [XIS 2.2.8.6] of T1 is equal to the value of the Abstract property [XIS 2.2.8.6] of T2 this condition is satisfied. Processors MUST raise a Concept Abstract event [EvAbstract] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

7. If the value of the Block property [XIS 2.2.8.7] of T1 is equal to the value of the Block property [XIS 2.2.8.7] of T2 this condition is satisfied. Processors MUST raise a Concept Block event [EvBlock] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

8. If the value of the Final property [XIS 2.2.8.9] of T1 is equal to the value of the Final property [XIS 2.2.8.9] of T2 this condition is satisfied. Processors MUST raise a Concept Final event [EvFinal] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

9. For each XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of T1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of T2 exist; both relationships are equivalent if they satisfy all conditions in section 2.2.4 below. Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 below.

10. For each XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of T1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of T2 exists; both relationships are equivalent if they satisfy all conditions in section 2.2.4 below. Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 below.

11. For each XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of T1 where a corresponding XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of T2 exists; both attributes are equivalent if they satisfy all conditions in section 2.2.7 below. Processors MUST raise a Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.7 below.

12. For each XML Element Information Item in the Children property [XIS 2.2.8.13] of T1 where a corresponding XML Element Information Item in the Children property [XIS 2.2.8.13] of T2 exists; both XML Elements are equivalent if they satisfy all conditions in section 2.2.6 below. Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.6 below.

Two XBRL Tuple Information Items [XIS 2.2.10] T1, which belongs to the From DTS, and T2, which belongs to the To DTS, are NOT equivalent if any of the following conditions exist.

1. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of T1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.8.10] of T2. In this case, Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

2. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.8.10] of T2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.8.10] of T1. In this case, Processors MUST raise a Concept From event [EvConceptRelationshipFrom] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] with the relationship identifier Error! Reference source not found. in the [To DTS] parameter.

3. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of T1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.8.11] of T2. In this case, Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

4. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.8.11] of T2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.8.11] of T1. In this case, Processors MUST raise a Concept To event [EvConceptRelationshipTo] with the two concept identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] with the relationship identifier Error! Reference source not found. in the [To DTS] parameter.

5. For any XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of T1 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.8.12] of T2. In this case, Processors MUST raise an Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters followed by an Attribute deleted event [EvAttributeDelete] with the attribute identifier Error! Reference source not found. in the [From DTS] parameter.

6. For any XML Attribute Information Item in the Attributes property [XIS 2.2.8.12] of T2 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.8.12] of T1. In this case, Processors MUST raise a Concept Attribute event [EvConceptAttribute] with the two concept identifiers Error! Reference source not found. as parameters followed by an Attribute added event [EvAttributeNew] with the attribute identifier Error! Reference source not found. in the [To DTS] parameter.

7. For any XML Element Information Item in the Children property [XIS 2.2.8.13] of T1 where a corresponding XML Element Information Item cannot be found in the Children property [XIS 2.2.8.13] of T2. In this case, Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters followed by a Element node deleted event [EvNodeDeleted] with the XML element identifier Error! Reference source not found. in the [From DTS] parameter.

8. For any XML Element Information Item in the Children property [XIS 2.2.8.13] of T2 where a corresponding XML Element Information Item cannot be found in the Children property [XIS 2.2.8.13] of T1. In this case, Processors MUST raise a Concept Child event [EvChild] with the two concept identifiers Error! Reference source not found. as parameters followed by a Element node added event [EvNodeNew] with the XML element identifier Error! Reference source not found. in the [To DTS] parameter.

2.2.4 Comparing two XBRL Relationship Information Items:

Two XBRL Relationship Information Items [XIS 2.2.14] R1, which belongs to the From DTS, and R2, which belongs to the To DTS, are equivalent if all the following conditions are satisfied and none of the “NOT equivalent” conditions below exist.

1. If the object in the From DTS pointed to by the From property [XIS 2.2.14.3] of R1 corresponds to the object in the To DTS pointed to by the From property [XIS 2.2.14.2] of R2 this condition is satisfied. Processors MUST add a Relationship Source event [EvSource] to the parent event with the two relationship identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2. If the object in the From DTS pointed to by the To property [XIS 2.2.14.4] of R1 corresponds to the object in the To DTS pointed to by the To property [XIS 2.2.14.4] of R2 this condition is satisfied. Processors MUST add a Relationship Target event [EvTarget] to the parent event with the two relationship identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

3. If each relationship in the relationship set that precedes R1 [XVS 2.1.1] in the From DTS corresponds to another relationship in the relationship set that precedes R2 [XVS 2.1.1] in the To DTS, or both relationships have no preceding relationship set this condition is satisfied. Processors MUST add a Relationship Previous event [EvPrevious] to the parent event with the two relationship identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

4. If each relationship in the relationship set that follows R1 [XVS 2.1.2] in the From DTS corresponds to another relationship in the relationship set that follows R2 [XVS 2.1.2] in the To DTS, or both relationships have no a following relationship set this condition is satisfied. Processors MUST add a Relationship Next event [EvNext] to the parent event with the two relationship identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

5. If the value of the Priority property [XIS 2.2.14.8] of R1 is equal to the value of the Priority property [XIS 2.2.14.8] of R2 this condition is satisfied. Processors MUST add a Relationship Priority event [EvPriority] to the parent event with the two relationship identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

6. For each XML Attribute Information Item in the Attributes property [XIS 2.2.14.9] of R1 where a corresponding XML Attribute Information Item in the Attributes property [XIS 2.2.14.9] of R2 exists; both attributes are equivalent if they satisfy all conditions in section 2.2.7 below. Processors MUST add a Relationship Attribute event [EvRelationshipAttribute] with the two relationship identifiers Error! Reference source not found. to the parent event if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.7 below.

Two XBRL Relationship Information Items [XIS 2.2.14] R1, which belongs to the From DTS, and R2, which belongs to the To DTS, are NOT equivalent if any of the following conditions exist.

1. For any XML Attribute Information Item in the Attributes property [XIS 2.2.14.9] of R1 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.14.9] of R2. In this case, Processors MUST add a Relationship Attribute event [EvRelationshipAttribute] with the two relationship identifiers Error! Reference source not found. to the parent event followed by a Attribute deleted event [EvAttributeDelete] with the attribute identifier Error! Reference source not found. in the [From DTS] parameter.

2. For any XML Attribute Information Item in the Attributes property [XIS 2.2.14.9] of R2 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.14.9] of R1. In this case, Processors MUST add a Relationship Attribute event [EvRelationshipAttribute] with the two relationship identifiers Error! Reference source not found. to the parent event followed by a Attribute added event [EvAttributeNew] with the attribute identifier Error! Reference source not found. in the [To DTS] parameter.

2.2.5 Comparing two XBRL Resource Information Items:

Two XBRL Resource Information Items [XIS 2.2.15] X1, which belongs to the From DTS, and X2, which belongs to the To DTS, are equivalent if all the following conditions are satisfied and none of the “NOT equivalent” conditions below exist:

1. If the value of the Type property [XIS 2.2.15.2] of X1 is equal to the value of the Type property [XIS 2.2.15.2] of X2 this condition is satisfied. Processors MUST raise a Resource Type event [EvResourceType] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2. If the value of the URI property [XIS 2.2.5.4] of the XBRL Role Type Information Item [XIS 2.2.5] referenced in the Role property [XIS 2.2.15.3] of X1 is equal to the value of the value of the URI property [XIS 2.2.5.4] of the XBRL Role Type Information Item [XIS 2.2.5] referenced in the Role property [XIS 2.2.15.3] of X2 this condition is satisfied. Processors MUST raise a Resource Role event [EvRole] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

3. For each XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.15.5] of X1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.15.5] of X2 exist; both relationships are equivalent if they satisfy all conditions in section 2.2.4 above. Processors MUST raise a Resource From event [EvResourceFrom] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 above.

4. For each XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.15.6] of X1 where a corresponding XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.15.6] of X2 exists; both relationships are equivalent if they satisfy all conditions in section 2.2.4 above. Processors MUST raise a Resource To event [EvResourceTo] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.4 above.

5. For each XML Attribute Information Item in the Attributes property [XIS 2.2.15.7] of X1 where a corresponding XML Attribute Information Item in the Attributes property [XIS 2.2.15.7] of X2 exists; both attributes are equivalent if they satisfy all conditions in section 2.2.7 below. Processors MUST raise a Resource Attribute event [EvResourceAttribute] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.7 below.

6. If the resource has complex content and for each node N1 in the sequence of nodes of the Element property [XIS 2.2.15.4] of X1; a node N2 exist that is the node in the same position in the sequence of nodes in the Element property [XIS 2.2.15.4] of X2 and N1 is s-equal2 to the node N2 (except for the attributes in the XLINK namespace and the id attributes that must be skipped) this condition is satisfied. Processors MUST raise a Resource Content event [EvContent] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied. This event will be the parent of additional events according to section 2.2.6 below.

7. If the resource has simple content and the value of the Value property [XIS 2.2.15.8] of X1 is s-equal2 to the value of the Value property [XIS 2.2.15.8] of X2 this condition is satisfied. Processors MUST raise a Resource Value event [EvValue] with the two resource identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

Two XBRL Resource Information Items [XIS 2.2.15] X1, which belongs to the From DTS, and X2, which belongs to the To DTS, are NOT equivalent if any of the following conditions exist:

8. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.15.5] of X1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.15.5] of X2. In this case, Processors MUST raise a Resource From event [EvResourceFrom] with the two resource identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

9. For any XBRL Relationship Information Item [XIS 2.2.14] in the From property [XIS 2.2.15.5] of X2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the From property [XIS 2.2.15.5] of X1. In this case, Processors MUST raise a Resource From event [EvResourceFrom] with the two resource identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] event with the relationship identifier Error! Reference source not found. as a parameter.

10. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.15.6] of X1 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.15.6] of X2. In this case, Processors MUST raise a Resource To event [EvResourceTo] with the two resource identifiers Error! Reference source not found. as parameters followed by a Relationship deleted event [EvRelationshipDelete] with the relationship identifier Error! Reference source not found. in the [From DTS] parameter.

11. For any XBRL Relationship Information Item [XIS 2.2.14] in the To property [XIS 2.2.15.6] of X2 a corresponding XBRL Relationship Information Item [XIS 2.2.14] cannot be found in the To property [XIS 2.2.15.6] of X1. In this case, Processors MUST raise a Resource To event [EvResourceTo] with the two resource identifiers Error! Reference source not found. as parameters followed by a Relationship added event [EvRelationshipNew] with the relationship identifier Error! Reference source not found. in the [To DTS] parameter.

12. For any XML Attribute Information Item in the Attributes property [XIS 2.2.15.7] of X1 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.15.7] of X2. In this case, Processors MUST raise a Resource Attribute event [EvResourceAttribute] with the two resource identifiers Error! Reference source not found. as parameters followed by an Attribute deleted event [EvAttributeDelete] with the attribute identifier Error! Reference source not found. in the [From DTS] parameter.

13. For any XML Attribute Information Item in the Attributes property [XIS 2.2.15.7] of X2 a corresponding XML Attribute Information Item cannot be found in the Attributes property [XIS 2.2.15.7] of X1. In this case, Processors MUST raise a Resource Attribute event [EvResourceAttribute] with the two resource identifiers Error! Reference source not found. as parameters followed by a Attribute added event [EvAttributeNew] with the attribute identifier Error! Reference source not found. in the [To DTS] parameter.

14. For any resource that has complex content and for each node N1 in the sequence of nodes of the Element property [XIS 2.2.15.4] of X1 a node N2 that is the node in the same position in the sequence of nodes in the Element property [XIS 2.2.15.4] of X2 does not exist. In this case, a Processor MUST raise a Resource Content event [EvContent] with the two resource identifiers Error! Reference source not found. as parameters followed by an Element node deleted event [EvNodeDeleted] with the XML Element Identifier Error! Reference source not found. in the [From DTS] parameter.

15. For any resource that has complex content and for each node N2 in the sequence of nodes of the Element property [XIS 2.2.15.4] of X2 a node N1 that is the node in the same position in the sequence of nodes in the Element property [XIS 2.2.15.4] of X1 does not exist. In this case, a Processor MUST raise a Resource Content event [EvContent] with the two resource identifiers Error! Reference source not found. as parameters followed by an Element node added event [EvNodeNew] with the XML Element Identifier Error! Reference source not found. in the [To DTS] parameter.

2.2.6 Comparing two XML Element Information Items:

Two XML Element Information Items E1, which belongs to the From DTS and E2, which belongs to the To DTS, are equivalent if the following condition is satisfied:

1. If E1 and E2 are s-equal2 nodes except for the attributes in the XLINK namespace and the id attribute this condition is satisfied. Processors MUST add a Not s-equal2 nodes event [EvNodesInequality] to the parent event with the two element identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2.2.7 Comparing two XML Attribute Information Items:

Two XML Attribute Information items A1,which belongs to the From DTS and A2, which belongs to the To DTS are equivalent if the following condition is satisfied:

2. If A1 and A2 are s-equal2 nodes this condition is satisfied. The s-equal2 predicate is defined in section 2.3 below. Processors MUST raise a Not s-equal2 attributes event [EvAttributesInequality] to the parent event with the two attribute identifiers Error! Reference source not found. as parameters if this condition is not satisfied.

2.2.8 Comparing two Schema Type Definitions:

This document does not impose any specific XSD object model, but the definition of equality of two XML types is necessary in order to properly implement a mechanism that identifies if an item, tuple or resource definition has changed from one taxonomy version to another.

Therefore, it is the responsibility of the vendor specific object model to provide information about the equality of item, tuple and resource data types.

As long as two different XSD data types are recognized as not equal, the amount of information provided about the differences is vendor dependant.

The XVS conformance suite provides a minimum set of test cases about differences in data type definitions. Processors MUST recognize changes in XSD data types at least for the use cases defined in the XVS conformance suite.[HW1] [ihr2]

2.3 Definition of the s-equal2 predicate between two sequences of XML nodes:

The s-equal2 predicate is identical to the s-equal predicate defined in section 4.10 of the [XBRL] specification replacing XPath 1.0 with XPath 2.0 in the definition of the x-equal operation for the cases in which the s-equal predicate relys on x-equality. XPath 2.0 equality MUST be performed with the "XPath 1.0 compatibility mode" property set to false in the static context (See the implementation note below).

IMPLEMENTATION NOTE (non-normative): The [XBRL] 2.1 specification is based on XPath 1.0. According to section 5.3 of the XPath 1.0 specification, the content of attributes is always a string-value rather than a QName. XBRL APIs implementing the equivalence operation between XML Information Items should take care of this and normalize the prefixes of QNames in order to effectively compare QNames and not their lexical representation.

2.4 Rules of correspondence between Information Items

Section 2.2 of this specification compares two information items that correspond one (in the From DTS) to the other (in the To DTS). Only two information items that correspond are subject to be compared to detect “technical differences”. The rules of correspondence of two information items are described in this section.

Two information items A and B correspond if they are of the same type and satisfy all conditions in the.appropriate section according to the information item type.

2.4.1 Correspondence of Concept Definitions

Two concept definitions A and B are in correspondence if there is at least one Diff Event [Def 1] in the versioning report that contains the concept identifier Error! Reference source not found. of concept A in the [From DTS] parameter and the concept identifier Error! Reference source not found. of concept B in the [To DTS] parameter.

2.4.2 Correspondence of Relationships

Two relationships A and B are in correspondence if all the following conditions are satisfied:

· The correspondent Information Item of the content of the From property [XIS 2.2.14.3] of relationship A is the Information Item in the content of the From property [XIS 2.2.14.3] of relationship B. For the identification of the correspondent content in the From property [XIS 2.2.14.3] of the relationship A the appropriate section 2.4.1, 2.4.3 or 2.4.5 must be used according to the content type, and

· The URI pair [Def 6] of the URI property [XIS 2.2.5.4] of the role property [XIS 2.2.12.3] of the Extended Link [XIS 2.2.12] that is the Parent property [XIS 2.2.14.1] of the relationship A is equal to the value of the URI property [XIS 2.2.5.4] of the role property [XIS 2.2.12.3] of the Extended Link [XIS 2.2.12] that is the Parent property [XIS 2.2.14.1] of the relationship B, and

· The Type property [XIS 2.2.14.2] of relationship A is equal to the Type property [XIS 2.2.14.2] of relationship B, and

· The URI property [XIS 2.2.6.4] of the Arcrole property [XIS 2.2.14.5] of relationship A is equal to the URI property [XIS 2.2.6.4] of the Arcrole property [XIS 2.2.14.5] of relationship B, and

· The correspondent Information Item of the content of the To property [XIS 2.2.14.4] of relationship A is the Information Item in the content of the To property [XIS 2.2.14.4] of relationship B. For the identification of the correspondent content in the To property [XIS 2.2.14.4] of the relationship A the appropriate section 2.4.1, 2.4.3 or 2.4.5 must be used according to the content type.

2.4.3 Correspondence of Resources

Two resources A and B are in correspondence if there is at least one Diff Event [Def 1] in the versioning report that contains the resource identifier Error! Reference source not found. of resource A in the [From DTS] parameter and the resource identifier Error! Reference source not found. of resource B in the [To DTS] parameter.

2.4.4 Correspondence of XML Attributes

Two Attribute Information Items A1 and A2 are in correspondence if their node names are equal. The attribute value is not used to find the correspondent attribute of another attribute.

2.4.5 Correspondence of XML Element Nodes

Two XML Element nodes N1 and N2 are in correspondence if they are s-equal2 nodes.

2.5 Hierarchical organization of the events

The events documenting the “technical differences” are organized according to the following table:

Code	Event	Parent Event	From DTS	To DTS	Final
[EvConceptDelete]	Concept deleted	None	Error! Reference source not found.	-	Yes
[EvConceptNew]	Concept added	None	-	Error! Reference source not found.	Yes
[EvConceptNoChangeEvent]	Concept equivalency	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvConceptNamespace]	Concept namespace	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvConceptName]	Concept name	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvConceptType]	Concept Type	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvSubstitutionGroup]	Concept Substitution Group	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvPeriodType]	Concept Period Type	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvNillable]	Concept Nillable	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvAbstract]	Concept Abstract	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvBlock]	Concept Block	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvBalance]	Concept Balance	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvDefault]	Concept Default	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvFixed]	Concept Fixed	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvFinal]	Concept Final	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvConceptRelationshipFrom]	Concept From	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvConceptRelationshipTo]	Concept To	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvConceptAttribute]	Concept Attribute	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvChild]	Concept Child	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvAttributeDelete]	Attribute deleted	[EvConceptAttribute] or [EvRelationshipAttribute] or [EvResourceAttribute]	Error! Reference source not found.	-	Yes
[EvAttributeNew]	Attribute added	[EvConceptAttribute] or [EvRelationshipAttribute] or [EvResourceAttribute]	-	Error! Reference source not found.	Yes
[EvAttributesInequality]	Not s-equal2 attributes	[EvConceptAttribute] or [EvRelationshipAttribute] or [EvResourceAttribute]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvNodeDeleted]	Element node deleted	[EvChild] or [EvContent]	Error! Reference source not found.	-	Yes
[EvNodeNew]	Element node added	[EvChild] or [EvContent]	-	Error! Reference source not found.	Yes
[EvNodesInequality]	Not s-equal2 nodes	[EvChild] or [EvContent]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvRelationshipDelete]	Relationship deleted	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	-	Yes
[EvRelationshipNew]	Relationship added	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	-	Error! Reference source not found.	Yes
[EvSource]	Relationship Source	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvTarget]	Relationship Target	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvPrevious]	Relationship Previous	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvNext]	Relationship Next	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvPriority]	Relationship Priority	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvRelationshipAttribute]	Relationship Attribute	[EvConceptRelationshipFrom] or [EvConceptRelationshipTo] or [EvResourceFrom] or [EvResourceTo]	Error! Reference source not found.	Error! Reference source not found.	No
[EvResourceDelete]	Resource deleted	None	Error! Reference source not found.	-	Yes
[EvResourceNew]	Resource added	None	-	Error! Reference source not found.	Yes
[EvResourceNoChangeEvent]	Resource equivalency	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvResourceType]	Resource Type	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvRole]	Resource Role	None	Error! Reference source not found.	Error! Reference source not found.	Yes
[EvResourceFrom]	Resource From	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvResourceTo]	Resource To	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvResourceAttribute]	Resource Attribute	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvContent]	Resource Content	None	Error! Reference source not found.	Error! Reference source not found.	No
[EvValue]	Resource Value	None	Error! Reference source not found.	Error! Reference source not found.	Yes

2.6 Extensibility model of Events

Events in a versioning report are not limited to those defined in the table of section 2.5 above. This specification provides one abstract event called ver:EvOther that can be used in other specifications to define new events more appropriate to the content they are dealing with.

The only constraint for those new events is that they MUST be defined in the substitution group of the ver:EvOther event and the type definition MUST be a valid restriction of ver:nestedEventType. Refer to Part 2 of this document for more information about the limitations imposed by the ver:nestedEventType.

It is expected that extensions of this specification will provide new ways to identify a concept or a resource in a DTS. For this reason, the extensibility of the “technical differences” is complemented with the existence of two extensibility points to define new concept identifiers and new resource identifiers.

3 The content model of the versioning report

A versioning report is a set of one or more version information items.

A version information item is the set of information that documents what happened between to concepts or resources between two DTSs.

The content of a version information item is represented in figure 2 below.

Figure 2: Content of a version information item

Each one of the containers in the figure represents different pieces of information about changes made to a taxonomy.

Assignments can:

· group actions made to a DTS, and

· be categorized in order to allow business users to filter what information they want to access to, and

· be documented separately, and

· are optional content in a versioning report.

Actions can:

· group a set of ”technical differences” between the From DTS and the To DTS, and

· provide a semantic meaning about the change, and

· provide specific human readable documentation.

3.1 Complete versioning reports

Looking at the information in the versioning report as if it was a database, the in-scope documentation for a change is the result of a query that identifies the set of human readable documentation that satisfies the query conditions.

The query conditions can be completely generic or very explicit to a particular change event or change event path. The in-scope documentation can range from being as extensive as the whole report for generic queries to being as explicit as the documentation related to a specific action for a particular event made to a particular concept.

A complete versioning report MUST contain in-scope documentation for every “technical difference” represented as a Difference Path [Def 2] generated by conditions according to section 2.2 above.

This specification does not impose any requirement that versioning reports be complete.

The completeness of a versioning report can be validated by versioning processors implemented according to this specification.

3.2 The Concept A or Resource X component

This component represents concepts or resources defined in the From DTS.

When a concept or resource defined in the To DTS has no correspondence with any concept or resource defined in the From DTS there is no concept or resource A component in the event.

Concepts or resources referenced in this component can have a one to many relationship with Actions.

3.3 The Concept B or Resource Y component

This component represents concepts or resources defined in the To DTS.

When a concept or resource defined in the From DTS has no correspondence with any concept or resource defined in the To DTS there is no concept or resource B component in the event.

Concepts or resources referenced in this component can have a one to many relationship with Actions.

3.4 The Assignment component

This is a container of human readable documentation related to the reasons for a set of actions.

The existence of assignments in a versioning report is optional.

Assignments can be categorized.

An assignment with no relationships to actions represents unimplemented but solicited changes to a DTS.

3.5 The Action component

This is a container of a set of multiple events and documentation connected to the concept or resource referenced in the Concept or resource A component and/or the Concept or resource B component.

Action components may be referenced from one or more assignments. Action components are not required to be referenced by any assignment.

An action component referenced from Concept or resource A components and with references to Concept or resource B components represents changes made to the concept or resource definitions that are in correspondence.

Action components referenced from Concept or resource A components without references to Concept or resource B components represents concepts deleted from the From DTS.

Action components referencing Concept or resource B components without being referenced by Concept or resource A components represents new concepts added to the To DTS.

Action components may contain no events. In this case they play the role of a container for generic information related to the new version of the DTS.

3.6 The Event component

An Event is a container of a set of zero or more differences between the From DTS and the To DTS.

Differences can be grouped together in a set to provide semantic meaning to the Event. The semantic meaning of different groups of differences is defined in table Error! Reference source not found. in Part 2 of this specification.

A single Action may have zero or more Events.

3.7 The Differences component

This component represents one Difference Path [Def 2].

3.8 The Categories component

This box represents a set of code categories for the changes. There are some pre-defined categories in this specification.

a. Errata

b. Business

c. Technical

Each project is able to define new sub categories of these categories.

3.9 The Documentation component

This is represents the text of the human readable documentation for the in-scope change event.

3.10The Version component

This component is the container of a versioning report between two DTSs. It contains information about the DTSs where Concept A or Resource X and Concept B or Resource Y are defined. This information includes:

a. The starting point of the DTS Concept A or Resource X belongs to.

b. The starting point of the DTS Concept B or Resource Y belongs to.

c. Optionally, references to other versioning reports.

d. Optionally, the namespace mapping information that identifies the correspondence between namespace definitions in the From DTS and namespace definitions in the To DTS.

e. Optionally, the role mapping information that identifies the correspondence between role URIs used in the From DTS and role URIs used in the To DTS.

The namespace mapping information is a set of namespace pairs identifying which is the From and To namespaces.

[Def 5] The namespace pair of the From namespace is the To namespace defined in the namespace mapping or the same From namespace if none is explicitly defined in the namespace mapping. This relationship is symmetric.

The role mapping information is a set of URI pairs identifying which are the From URI and the To URI.

[Def 6] The role URI pair of the From role URI is the To URI defined in the role mapping or the same From URI if none is explicitly defined in the role mapping. This relationship is symmetric.

The concept mapping information is a set of QName pairs identifying which are the From concept QName and the To concept QName. The concept mapping table is not explicitly written in the versioning report but obtained from the [From DTS] and [To DTS] parameters in the Diff Events.

[Def 7] The concept pair of a From concept QName is the To concept QName defined in the concept mapping or the same From concept QName if none is explicitly defined in the concept mapping. This relationship is symmetric.

The resource mapping information is a set of XPointer reference pairs identifying which are the From resource and the To resource. The resource mapping table is not explicitly written in the versioning report but obtained from the [From DTS] and [To DTS] parameters in the Diff Events.

[Def 8] The resource pair of a From resource is the To resource defined in the resource mapping table. This relationship is symmetric.

4 The versioning report syntax

The syntax of the versioning report is specified in a separate document XVS Part 2.

A References

[RFC2119]	Scott Bradner
	Key words for use in RFCs to Indicate Requirement Levels, March 1997
	http://www.ietf.org/rfc/rfc2119.txt

[SCHEMA-0]	World Wide Web Consortium.
	XML Schema Part 0: Primer.
	http://www.w3.org/TR/xmlschema-0/

[SCHEMA-1]	World Wide Web Consortium.
	XML Schema Part 1: Structures.
	http://www.w3.org/TR/xmlschema-1/

[SCHEMA‑2]	World Wide Web Consortium.
	XML Schema Part 2: Datatypes.
	http://www.w3.org/TR/xmlschema-2/

[XINFOSET]	XML Information Set (Second Edition)
	W3C Recommendation 4 February 2004
	http://www.w3.org/TR/xml-infoset/

[XBRL]	Phillip Engel, Walter Hamscher, Geoff Shuetrim, David vun Kannon, Hugh Wallis.
	Extensible Business Reporting Language (XBRL) 2.1 Recommendation with corrected errata to 2006-12-18
	http://www.xbrl.org/SpecRecommendations/

[XLINK]	Steve DeRose, Eve Maler, David Orchard
	XML Linking Language (XLink) Version 1.0.
	http://www.w3.org/TR/xlink/

[XPATH]	Anders Berglund, Scott Boag, Don Chamberlin, Mary F. Fernández, Michael Kay, Jonathan Robie, Jérôme Siméon.
	XML Path Language (XPath) 2.0
	http://www.w3.org/TR/xpath20/

[XML Base]	Jonathan Marsh
	XML Base.
	http://www.w3.org/TR/xmlbase/

[XPTR]	Paul Grosso, Eve Maler, Jonathan Marsh, and Norman Walsh, editors
	XML Pointer Language (XPointer Framework) V1.0.
	http://www.w3.org/TR/xptr-framework/

[XIS]	Ignacio Hernández-Ros
	XBRL Infoset
	Not yet publicly available

[VREQ]	Sergio Quiroz and Katrin Schmehl, editors
	Versioning Specification Requirements
	Not yet publicly available

B Requirements Reference (non-normative)

This section cross references to the versioning requirements [VREQ].

ID	PRINCIPLE		MEANING			Satistied
P1	Consistency		XBRL concepts and terminology should be used to describe the solution. In particular, versioning components should be described using XBRL related technologies as taxonomies, linkbases, XLink, XML Schema and others.			Yes
P2	No Redundancy		The solution should not require instances, schemas or linkbases to encode the same information in multiple places.			TBD
P3	Simplicity		The solution must not include features for which there is no documented need.			TBD
P4	Priority		An implementation of these requirements must not violate the most current edition of the XBRL 2.1 specification.			Yes
P5	Usability		It must be possible to implement the solution in software in a user friendly manner for both: the taxonomy authors who want to create new versions of their taxonomies and for instance document authors who must adapt their systems to produce documents according to new the new taxonomy versions. If something in the design were in conflict between the two groups defined above the point of view that should prevalence is the one that gives more simplicity to the instance document authors			Yes
P6	Compatibility		The solution SHOULD be compatible with current XBRL Taxonomies and Taxonomies that are using XBRL modules that are based on XBRL technology, such as the Dimensions Specification 1.0 and the Formula Linkbase Specification.			Yes
U1101	New XBRL concept		The adding of a new item [[XIS] 2.2.8 + [XIS] 2.2.9] or a new tuple [[XIS] 2.2.8 + XIS 2.2.10] MUST be documented.			Yes
U1102	Deletion of an XBRL concept		The deletion of an item [XIS 2.2.8 + [XIS] 2.2.9] or a tuple [[XIS] 2.2.8 + [XIS] 2.2.10] MUST be documented.			Yes
U1201	Change in the QName		If a concept QName [[XIS] 2.2.3.2 + XIS 2.2.8.2] has changed, this change MUST be documented.			Yes
U1202	Change in the ID attribute value		If an element ID has changed may be to correspond with the element name, this change should NOT be documented.			Yes
U1203	Change in the substitutionGroup attribute value		A change in the substitutionGroup [[XIS] 2.2.8.4] MUST be documented.			Yes
U1204	Change in the abstract attribute value		If the abstract attribute value [[XIS] 2.2.8.6] has changed, this change MUST be documented.			Yes
U1205	Change in the nillable attribute value		If the nillable attribute value [[XIS] 2.2.8.5] has changed, this change MUST be documented.			Yes
U1206	Change in the type definition		If the type definition [[XIS] 2.2.8.3] has changed, this change MUST be documented.			Yes
U1207	Change in the periodType attribute value		If the periodType attribute value [[XIS] 2.2.9.2] has changed, this change MUST be documented.			Yes
U1208	Change in the balance attribute value		If the balance attribute value [[XIS] 2.2.9.3] has changed, this change MUST be documented.			Yes
U1209	Change in the block attribute value		If the block attribute value [[XIS] 2.2.8.7] has changed, this change MUST be documented.			Yes
U1210	Change in the default attribute value		If the default attribute value [[XIS] 2.2.9.4] has changed, this change MUST be documented.			Yes
U1211	Change in the fixed attribute value		If the fixed attribute value [[XIS] 2.2.8.8] has changed, this change MUST be documented.			Yes
U1212	Change in the final attribute value		If the final attribute value [[XIS] 2.2.8.9] has changed, this change MUST be documented.			Yes
U1213	Change of a child element		If a new child [[XIS] 2.2.8.13] has been added, deleted or changed inside a tuple element, this change MUST be documented.			Yes, but due to changes in the data type only.
U1214	Change in additional attributes		Changes on additional attributes [[XIS] 2.2.8.12] MUST be documented.			Yes
U1215	New relationship		If a new relationship [[XIS] 2.2.8.10 + [XIS] 2.2.8.11] has been added to a concept where the concept acts as source or target, this change MUST be documented.			Yes
U1216	Deletion of a relationship		If a relationship [[XIS] 2.2.8.10 + [XIS] 2.2.8.11] refering to a concept does no longer exist, this change MUST be documented.			Yes
U1217	New resource		The addition of a new resource [[XIS] 2.2.15] linked to a concept i.e. a label or a reference MUST be documented.			Yes
U1218	Deletion of a resource		If a resource [[XIS] 2.2.15] referenced by a concept has been deleted, this change MUST be documented.			Yes
U1219	New attribute		If an attribute has been added to a concept, this change MUST be documented.			Yes
U1220	Deletion of an attribute		The deletion of an attribute of a concept MUST be documented.			Yes
U1301	Change in the URI of an extended link role		A change in the URI of an extended link role MUST be documented.			Yes, in the mapping rules
U1303	Change in the arcrole type		If the arcrole type [[XIS] 2.2.14.5] has changed, this change MUST be documented.			No, a deletion of the old relationship and creation of a new relationship is documented
U1305	Change in the order attribute value		If the order attribute value [[XIS] 2.2.14.6] has changed, this change should only be documented when the ordering of the concepts has changed.			Yes
U1306	Change in the highest priority relationship(s)		When the highest priority relationship(s) [[XIS] 2.2.14.8] has changed, this change MUST be documented. Changes on relationship(s) with lower priority should not be documented.			Yes
U1307	Change in additional attributes		Changes on additional attributes [[XIS] 2.2.14.9] MUST be documented.			Yes
U1308		Addition of an attribute		If an attribute has been added to a relationship, this change MUST be documented.	Yes
U1309		Deletion of an attribute		The deletion of an attribute of a relationship MUST be documented.	Yes
U1401	Change in the role attribute		If there is a change in the definition of a role attribute [[XIS] 2.2.15.3] of a resource, this change MUST be documented.			Yes
U1402	Change of the content of a resource		If the content of a resource [[XIS] 2.2.15.8] has changed, this change MUST be documented.			Yes
U1501	Add a documentation for a change		If an addition, deletion or a change has been made, the taxonomy editor should be able to add an explanation for this change.			Yes
U1502	Add a documentation of a group of changes		If changes can be grouped, it should be possible to add documentation for a summary of changes: examples include splitting of concepts, collapsing of concepts etc.			Yes
U1503	Additional information for change documentation		The following information should be possible to include in the change documentation: Error description, change description, found by, severity, change date. It would be preferable to have a structural and extensible documentation.			Yes
U1504	Add a change category		It should be possible to add a change category to distinguish if a change is due to an error, a new requirement, change that affect automated processing or do not affect automated processing etc. A short list of predefined change categories should be provided but also a possibility to add new categories.			Yes
U1505	No documentation of syntactical changes		If the changes have no semantics so that they are only syntactical, these changes should no be documented. For example a resource like a label moves from one linkbase file to another.			Yes
U1506	Multi-lingual documentation		It should be possible to add documentation on a change in different languages.			Yes
U1601	Give information about the completeness of a versioning report		If a versioning report contains only a limited number of changes because unrelevant changes are left out. The versioning report should contain information that not all changes are listed.			Yes (in the queue)
U1602	Information about compatibility		It should be possible to add information about the backward and forward compatibility of the old and new version of a taxonomy.			Not in this specificatiom, a versioning report could be included in a IXBRL report that would suite this needs.
U1603	Additional metadata		It should be possible to add metadata to document who created the versioning report, including additional contact information.			See U1602
U1604	Add information about the versioning strategy		It should be possible to add information about the versioning strategy.			See U1602
U1605	Give information about the mapping rules		A version report should also list the mapping rules that are the basis of the generated report.			Yes
U1701		Detect equivalent dimensional relationships		If a dimensional relationship has only syntactical changes, these changes should not be reported (i.e. the composition of a hypercube has changed or it is divided but the relationships between primary and dimensional elements are the same).	Yes, by using extensibility points defined in this specification
U1702		Change on the dimensional representation of a set of concepts		Changes on the dimensional representation of a concept: a concept doesn't change from a business perspective, but it's XBRL dimensional representation does. I.E: Version 1 Version 2 A <==> X ( D = d1 ) B <==> X ( D = d2 ) C <==> X ( D = d3 ) Where A, B, C and X are primary items, D is a dimension and d1, d2 and d3 are domain members of a dimension. It should be possible to express this kind of equivalences so that ETL tools and others would be able to update mappings according to this information	Yes, by using extensibility points defined in this specification
U2101	Choose the level of detail		It should be possible to choose if the level of detail as well as not to list unrelevant changes in a versioning report.			This is a requirement for tools consuming the versioning report. This spec guarantees that this will be possible to implement
U2102	Creation of a version report		The version report should be created in XBRL syntax as well as in a human readable form ( i.e. HTML). It should be also possible to extract business-oriented changes for an excerpt report addressed to business people.			Yes
U2103	Change documentation		XBRL software including versioning techniques should be able to add documentation on individual changes and group changes in a combined documentation.			Yes
U2104	Process of a versioning report		A versioning report should be technically readable to enable, whenever possible, dynamic processing of the changes.			Yes
U2105	Changes on instances		XBRL software including versioning techniques should support users to take into account the taxonomy changes in corresponding instances.			No
U2106	Capture versioning information during development		It should be possible to capture versioning information during the development phase of a taxonomy. XBRL software including versioning techniques should provide a set of services for taxonomy change management.			Yes
U2107	Change report		In case of changes on existing elements and attributes, the versioning report should show the old and the new value.			No, this contradicts P2. The information is always available in the source and target DTS. Applications consuming a versioning report can do this.
U2108	Business-oriented versioning report		It should be possible to create a human readable versioning report oriented to business people, for example, based on the change category. It should not include technical changes and not present the changes in an IT-based reporting language like HTML.			TBD
U2109	Impact analysis		XBRL software including versioning techniques should be able to make the impact analysis on calculation linkbase, dimensional relationships, formula linkbase (in the future). It should be possible to infer that a change on a concept in a new version has a potential impact on every concept that depends on the changed one.			This spec is designed in a way that applications consuming the versioning report can produce this information.
U2120	Comparison of extension taxonomies		XBRL software including versioning techniques should be able to compare two different extension taxonomies.			Yes
U2121	Process of extension taxonomies		XBRL software should provide support for taxonomy editors to adopt changes in the base taxonomy.			Yes
U2201	It MUST be possible to assert that a versioning report is complete, and to validate this assertion.		It is important that a versioning report documents all relevant changes. In some cases this will correspond to all the changes DTS being documented. In other cases, just a subset will be documented. Where all changes in the DTS are being documented, it would be useful to assert that this is the case so that the completeness of the report can be verified by third parties.			Not yet in the document but yes.
U3101	New entry point		An additional entry point should be documented; for example, a new taxonomy has been added to the XBRL framework.			No
U3102	Entry point removed		If an entry point has been removed by the taxonomy editor, this change should be documented.			No
U3103	Changes in the URI of entry points		If the URI has changed, this change should be documented.			No
U3104	New base taxonomy		An additional base taxonomy should be documented.			No
U3105	Base taxonomy removed		The deletion of a referenced base taxonomy should be documented.			No
U3106	Changes to the URI of the base taxonomy		If the URI has changed (for example, because of a new version that is now used), this change should be documented.			No
U3107	Changes on the base taxonomy		If the changes relate to an extension taxonomy, changes in the base taxonomy itself should not be documented.			No
U3108	Changes on documentary information		The changes in documentary information of the taxonomy header should be documented.			No
U3109	Version numbering		It should be possible to add a numbering for the versions.			No
U3110	Validity period		The taxonomy header should contain information about the validity period of a taxonomy.			No
U3201	Add a validity to a concept		It should be possible to define a validity for a concept and to validate this restriction.			No
U3202	Define a dynamic change		It should be possible to define that changes have a dynamic character and might be valid only for a special period. Explanation: A new version of the taxonomy should be published each time a new requirement has to be included or a “bugs fixing” is needed. If some concepts included in the taxonomy are very changeable (e.g. securities or vital statistics about geography or people), a very frequent update of the taxonomy is needed. Usually, Regulators do not publish a new version each time “something” has changed, but only with a view to the whole business process, so the validity period of the new version is related to the business scope. This would mean that the information about the actual “life” of dynamic concepts are, usually, lost. In fact, it is possible to assume that: When the concept is included in the new version, then its existence validity is equal to the version validity period When the concept is not included in the new version, then its “death” agrees with the end-date of the previous version validity period In both cases, this may be not true for dynamic concepts. Because of it’s important to collect facts considering exactly the “existence” of the related concepts (think about “multidimensional data”) so it’s important to properly document dynamic “real world changes”.			No
U3301	Detect equivalent dimensional relationships		If a dimensional relationship has only syntactical changes, these changes should not be reported (i.e. the composition of a hypercube has changed or it is divided but the relationships between primary and dimensional elements are the same).			No

C Intellectual Property Status

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to XBRL International or XBRL organizations, except as required to translate it into languages other than English. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).

This document and the information contained herein is provided on an "AS IS" basis and XBRL INTERNATIONAL DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

The attention of users of this document is directed to the possibility that compliance with or adoption of XBRL International specifications may require use of an invention covered by patent rights. XBRL International shall not be responsible for identifying patents for which a license may be required by any XBRL International specification, or for conducting legal inquiries into the legal validity or scope of those patents that are brought to its attention. XBRL International specifications are prospective and advisory only. Prospective users are responsible for protecting themselves against liability for infringement of patents. XBRL International takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).

D Acknowledgements

This document is a result of careful consideration by the participants of the XBRL International Versioning Working Group. The XBRL International Versioning Working Group is chaired by Paul Warren (DecisionSoft) and vice chaired by Katrin Schmehl (Deutsche Bundesbank).

E Document History

Date	Editor	Summary
2007-01-04	IHR	First skeletal draft created.
2007-02-15	IHR	Updated Introduction and Background Added XPath 2.0 expressions on XBRL Information Items Added static definitions for role types defined in the XBRL 2.1 specification Lots of clarifications and notes added to properties on the elements.
2007-02-21	IHR	Updated properties are: Content of a Imported XBRL Information item MAY not exist Linkbases in a XBRL Taxonomy Information item are not ordered
2007-03-15	IHR	Updated XPath 2.0 expressions. Removed the XBRL Pointer of a Relationship Information Item and the XBRL Locator Information Item. Updated the Relationship Information Item. Sources and targets of a relationship are the objects pointed and not the locators that points to the objects.
2007-04-15	IHR	Shorter property names. Added section 2.3 about comparing the elements in the Versioning Infoset. The XBRL Infoset is now created on top of a generic XSD Infoset Revised the Infoset related to an XBRL Resource
2007-08-17	IHR	XIS property numbers synchronized with XIS-IWD-2007-08-07 Preceding relationship and Following relationships defined in section 2.1 Section 2.2 (the algorithm) updated to make it more implementable in software. Some parts of the algorithm still requires revision. Deleted events that cannot be raised because the properties are used to find the correspondent Information Item. EvNamespace and EvName. Added EvBalance and EvDefault. Parameters of the events has been updated. The algorithm is simplified because of the new definition of a Concept Information Item as the parent of Item and Tuple. Comparison of relationships updated. All rules for finding the correspondent Information Item are now grouped into a specific section. Rules for cocnpet and relationship matching updated. The Hierarchical organization of events updated to reflect changes in the wording. Added section 2.7 about the constraints of difference paths. Hopefully this section can be deleted in the future if a non recursive algorithm is feashible. Content model updated to reflect concept mappings.
2007-09-12	IHR	Section 2.1 some editorial changes The algorithm about how to compute the Previous and Next properties from information in the XBRL Inset has been explained in detail. Section 2.2 Added a reference to the tables of namespace mapping, role mapping and concept mapping as input for the diff algorithm to run. Section 2.2.1 Added the Resources property of a DTS Information Item to the algorithm (not tested in software yet) The wording of the generation of events has been changed according to the new events table and the events removed in the latest conf calls. Section 2.5 updated according to changes in the events structure and events deleted in the latest conf calls Section 2.6 has been deeply reworded. Added a new section B in the appendix with references to the requirements documentation.
2007-10-09	IHR	Added the syntax section Updated the wording in the diff conditions so it is not an algorithm anymore but the description of conditions satisfied by both information items being compared Updated the diagram in section 3. No PowerPoint documents included anymore. Updated the definition of a correspondent concept to the new Concept QName mapping table. Lots of wording changes everywhere.
2007-10-22	IHR	Added definition of 4 new terms (From DTS, To DTS, Action and Assignment) Event names: EvDeleteRelationship and EvNewRelationship changed to EvRelationshipDelete and EvRelationshipNew respectively The term Change Request has been changed to Assignment The word box within section 3 has been changed to container or component. Added cardinality indicators in figure of section 3 Added the definition of a version information item Added cardinality to containes in the Figure 2 Changes made to the versioning taxonomy The request concept definition has been changed to assignment Assignment is now in the categoryTupleType The action content model changed to remove the categories from there. Typo in EvReSourceTo. Now is EvResourceTo Typo in EvNewRelationship. Now is EvRelationshipNew Typo in EvDeleteRelationship. Now is EvRelationshipDelete ver:role attribute on Resource Ids is optional content not required content. ver:value attribute on Attribute Ids is required content. Two relationships are different if they have different content in one attribute. Typo in fragmentId. It was fragmetId and now is fragmented Updated the Requirements reference to contain the new requirements incorporated.
2007-11-02	IHR	Added wording on the Introduction and Background sections. Changed correspondence of resources in order to make them explicit in a resources mapping table. Defined a new ElementId different from the NodeId. ElementId works to refer to information out of the DTS and NodeId can only be used within another Id because it locates an XML element as child of another XML element. Section 3.10 added definition 8 regarding the resource mapping table.
2007-11-15	IHR	Editorial changes according to suggestions from Ronald Hommes. Removed event EvFixed from tuple comparison. It was unnecessary. Added a constraint to make explicit the declaration of namespace prefixes used in XPath expressions when the XPath expression is used in an attribute of an element. Changed status from IWD to DPWD.
2008-04-11	IHR	Updated from DPWD back to IWD Wording changes in the Abstract section Wording changes in the Introduction Namespace changed from 2007 to 2008. Redlined version of the document may show 20072008 rather than just 2008. This is due to a bug Word that does not remove from the final variable value the text deleted in a paragraph. XBRL Versioning, a new paragraph has been added to define “technical differences” and “semantic differences”. Figure 1 updated according to comments received by Geoff Shuetrim. Section 2.1, wording changes to better explain the content of the XBRL Infoset and state that this specification covers changes in resource definitions as well as changes in concept definitions. Section 2.2 other editorial wording changes there are no changes to the comparison rules. Section 2.4 Changed the definition of the correspondence of concept definitions and the correspondence of resource definitions due to the reason the no longer exist. Section 2.5 added the two new events related to documenting no changes in concept definitions and no changes in resource definitions. Deleted the unnecessary EvArcrole event. New section 2.6 explaining that the event model is extensible and how to extend it. Section 3, changed figure 2 according to comments received from Walter Hamscher and updated the versioning box to accommodate the new content. Section 3.1 wording changes to include part of the text in the previous section. The completeness of a versioning report is now easier to understand thanks to the new definitions. Section 3.10 changed to accommodate the new content of the version component and the removal of the concept mapping table and resource mapping table. Section 4. Several changes: reworded the sections that suffered impact of the changes in the taxonomy and the addition of the new extensibility points. Relevant changes in section 4.3.3 to accommodate the new extensibility points at the time to define a concept identifier or a resource identifier. Appendix B requirements Reference has been updated because this new release of the document allows some requirements that was not addressed before. Versioning Taxonomy Summary has been updated.
2008-05-20		Chapter 4 (Syntax) moved into a different document (Part 2) Status changed from PWD into Draft Final Working Draft.
2008-05-22	Wallis	Editorial review and changes for publication. Rearranged sections dealing with conditions to be satisfied and not satisfied into a different logical structure for ease of understanding. Corrected title of document to Draft Public Working Draft (DPWD)
2008-05-28	IHR	Added a note to clarify that the versioning specification could also be used by companies reporting changes to their taxonomies. Reviewed editorial changes made by Hugh Wallis. Added changes according to comments from Herm Fischer. Revert document title to Internal Working Draft (IWD)
2008-06-03	Wallis	Minor editorial updates for wider distribution as IWD to other working groups.
2008-06-10	Wallis	Editorial to update to Draft PWD

[1] ETL stands for Extract, Transform and Load

[2] The XIS (XBRL Information Set) documentation defines the properties of every object in a DTS.

[3] Note that this is safe because this object is extended by other objects whose important properties are included as in the case of the namespace property of a XBRL Taxonomy Information Item.

[4] Two relationships belongs to the same extended link role if they have the same value in the URI property [XIS 2.2.5.4] of the Role Type Information Item that is the value of the role property [XIS 2.2.12.2] of the parent property [XIS 2.2.14.1] of each relationship.

Name	Contact	Affiliation
Ignacio Hernández-Ros	ignacio@reportingstandard.com	Reporting Estandar S.L.
Hugh Wallis	hughwallis@xbrl.org	XBRL International Inc.

Name	Contact	Affiliation
Timo Philipp	tphilipp@IASB.ORG.UK	IASC Foundation
Paul Warren	pdw@DECISIONSOFT.COM	DecisionSoft
Raynier van Egmond	rve@c3ismc.com	C3i SMC LLC.