Understanding Boolean and Enumeration Tags in Digital Reporting
This guest post is written by Catalina Ibáñez Gutiérrez and Carina Tepper from Lucanet Amana. Both are members of our Taxonomy Design Working Group.
Introduction:
The IFRS Foundation recently released its updated IFRS Accounting Taxonomy 2024 and the new IFRS Sustainability Disclosure Taxonomy. In early 2023, EFRAG published the first Draft ESRS Set 1 XBRL Taxonomy and Draft Article 8 XBRL Taxonomy and the final version was released in August 2024. In July 2024, GRI published the Draft GRI Sustainability Taxonomy.
These five new taxonomies share a common feature: the modelling of seminarrative (or categorical) concepts, using Booleans and enumerations.
Both ISSB and EFRAG use seminarrative (or categorical) modelling to streamline the interpretation of narrative disclosures in digital financial and sustainability reports, with the aim of enhancing the usability and comparability of narrative information. These elements empower users to efficiently extract and analyze narrative data presented in a structured format.
Note that Booleans and enumerated elements have been used in this way for several years in the US GAAP taxonomy.
Boolean Type:
Booleans are used for modelling seminarrative disclosures. As the term “seminarrative” already suggests, they are applied to text to provide more information about the content. As explained in iXBRL Tagging Features feature guidance, Boolean concepts may be used to indicate that specific, legally-required statements have been included in the report. Or in other words: Corresponds to a “yes” or “no” answer (true or false).
Boolean elements within XBRL taxonomies can for example serve as indicators, signaling whether certain statements or disclosures have been included in a financial or sustainability report. This simple true/false value streamlines reporting processes, ensuring clarity and accuracy in compliance with regulatory requirements.
For example, the companies need to disclose with true or false whether “performance metrics are included in remuneration policies”. In this example the area in the report where the disclosure requirement is mentioned is tagged, and since this is tagged with a Boolean, the information whether this is true or false is added as well.
Booleans do not require the inclusion of the phrase ‘yes’ or ‘no’ in the human-readable report.
IFRS Taxonomy usage
IFRS Foundation introduced categorical elements (Booleans) in addition to the existing narrative elements rather than as a replacement for those narrative elements. This approach is intended to help preparers capture both the categorical data and any related contextual information[1].
EFRAG usage
EFRAG further elaborates on the significance of Boolean elements within XBRL taxonomies. EFRAG categorizes Boolean types into three distinct categories following the ESRS standards[2]:
a) Simple Boolean: In the ESRS XBRL taxonomy all the disclosure requirements that include “whether” in the ESRS standard were translated into a simple Boolean. Companies can state clearly if they have done/applied something or not.
Now let’s see how EFRAG has converted an ESRS requirement into a simple Boolean: For example, ESRS E4, E4-2 paragraph 24 b): “The undertaking shall specifically disclose whether it has adopted… b) Sustainable land / agriculture practices or policies”
Corresponding Boolean: Sustainable land or agriculture practices or polices have been adopted.
There is also a special case of simple Boolean: a simple Boolean with a narrative element as its child, in this case the ESRS standards use “whether” and “how”. EFRAG implemented a Boolean to cover the “whether” and a text block covers the “how” for example:
In ESRS E4-2: paragraph 23 b) “In addition to the provisions of ESRS 2 MDR-P the undertaking shall describe whether and how its biodiversity and ecosystems-related policies:.. b) relate to its material biodiversity and ecosystems-related impacts”
Corresponding Boolean: Biodiversity and ecosystems-related policies to material biodiversity and ecosystems-related impacts.
Corresponding text block: Disclosure of how biodiversity and ecosystems-related policies to material biodiversity and ecosystems-related impacts.
b) Narrative (or conditional) Boolean: In the ESRS XBRL taxonomy all the disclosure requirements that require a positive or negative confirmation were translated in to a conditional Boolean. For example, if “no severe human rights incidents connected to own workforce have occurred”, the company shall state this with true or false. In this way EFRAG avoided the creation of a text block and, at the same time, improved the level of data comparability.
In ESRS S1-17 paragraph 104 a: “The undertaking shall disclose the following information regarding identified cases of severe human rights incidents (e.g., forced labour, human trafficking or child labour)…” If no such incidents have occurred, the undertaking shall state this.
Corresponding Boolean: No severe human rights incidents connected to own workforce have occurred
c) Technical Boolean: They were created to help link different pieces of information together. For example, a company needs to report about water risks and specify whether an action or recourse has been taken. This specific action or recourses is represented in the taxonomy with a technical Boolean: “action relates to area at water risk”. This Boolean indicates if related disclosure has been reported and makes it easier to find related information when searching through the data.
In ESRS E3-2 paragraph 19: “The undertaking shall specify actions and resources in relation to areas at water risk, including areas of high-water stress”
Corresponding Boolean: Action relates to area at water risk
GRI Usage
GRI explained that “Categorical Elements” — BooleanItemType — are valuable for reporting financial or business information that can be framed as “yes”/”no” or “true”/“false”. These data types are used in their taxonomy to reflect disclosure requirements, including conditions. In the GRI Sustainability Taxonomy, all BooleanItemType elements start with the word “Whether….”. For example:
- Whether the organization has consolidated financial statements that are audited.
- Whether financial information is filed on public record.
In some cases, a Boolean “Whether…“, is followed by a narrative element to capture complementary information, such as “How”, according to the wording in the Standards[3].
All Booleans
It is important to note, from a technical point of view, all Boolean types are the technically same for EFRAG, IFRS and GRI.
Enumerations
Enumerations[4] are the other element modeling seminarrative disclosures that has been introduced to the taxonomies. But how do enumerations differ from the Booleans? Booleans provide “Yes” or “No”, whereas enumerations allow preparers to choose from a wider choice of answers. choices “Short Term”, “Medium” and “Long Term” might be the answer. Do you want to include the industry a company belongs to? Just create an enumeration with all the industries you like.
To sum up, an enumeration can contain any set of options. There is even the possibility to either allow one answer only (single-valued, enumeration) or one or multiple answers (set-valued, enumerationSet).
Example of the implementation of a single choice enumeration in the ESRS XBRL Taxonomy from EFRAG:
In ESRS: PP-1, 5 (a)
“the undertaking shall disclose the following information: (a) whether the sustainability statement has been prepared on a consolidated or individual basis…”
Corresponding enumeration: Basis for preparation of sustainability statement.
Enumeration values: “Individual [Member]” and “Consolidated [Member]”.
Example of the implementation of a multiple choice enumeration in the ESRS XBRL Taxonomy from EFRAG:
In ESRS: E1-3 Ar.19 (b)
“When disclosing the information on actions as required under paragraphs 29 (a) and 29 (b), the undertaking may: (b) aggregate types of mitigation actions (decarbonisation levers) such as energy efficiency, electrification, fuel switching, use of renewable energy, products change, and supply-chain decarbonisation that fit the undertakings’ specific actions;…”
Corresponding enumeration: Decarbonisation lever type
Enumeration values:
“Energy and consumption reduction [Member]”,
“Material efficiency and consumption reduction [Member]”,
“Full switching [Member]”,
“Electrification [Member]”,
“Use of renewable energy [Member]”,
“Phase out, substitution or modification of product [Member]”,
“Phase out, substitution or modification of process [Member]”,
“Other decarbonization levers [Member]”, and
“Supply chain decarbonisation [Member]”.
Note that taxonomy navigation software may need to be adjusted to present enumeration concepts more intuitively, as the enumeration concept and its values are technically defined in the taxonomy separately. Now, let’s have a look at how the taxonomy creators defined their enumerations:
- ISSB IFRS Accounting Taxonomy Update 2 describes enumerations as allowing entities to choose an option from a predefined list or create entity-specific options if needed. There are two types: “set-valued extensible enumerations”, which permit multiple selections, and “single-valued extensible enumerations”, which allow only one selection[5].
- EFRAG Taxonomy defines Boolean types (yes/no) and enumeration item types (drop-down values) as seminarratives or categorical elements because they enrich unstructured narrative disclosures[6].
- GRI describes “Categorical Elements – Extensible Enumerations” as predefined lists (analogous to ‘drop-down menus’) within the taxonomy, enabling users to select the most appropriate item (single choice) or multiple items (multiple choices) from the list[7].
As we can see, all these definitions agree on the basic functionalities and all three taxonomies decided to use both the single-choice enumeration and multiple-choice enumeration.
But further down the line there are also some differences in how the taxonomy creators decided to design the enumerations. EFRAG decided to provide the option “Other” if nothing fits for an enumeration to avoid creating extensions. In the IFRS taxonomy it was decided to not include an “Other” element but encourage to create extensions.
Enumeration and hidden facts:
When you open an iXBRL report and look for an enumeration, you might see that it is included as a “hidden fact”[8]
The reason for this is simple: This item type has two components – one is the selected text value, and the other is the selected enumeration value(s). Since there are currently no transformations from the text value to the enumeration value(s), these must be stored somewhere. That place is as a hidden fact.
Typically, hidden facts are avoided because they break the link between what a person reads and what a computer extracts. For this reason, the latest changes to iXBRL transforms make it so these are no longer required. The changes are currently in public working draft status.
Summary
These elements encourage the users to not only mark the area where a certain topic is discussed, but also provide a clear answer on what this text means. This is especially helpful for machines to get more information out a Boolean or enumeration than they can get from a text block tag. But it is also helpful for the human reader as well to understand the information provided at a glance.
Furthermore, enumerations allow the filer to categorize elements further (if e.g. used for time frames).
These seminarrative elements play a vital role in all three EFRAG, IFRS and GRI reporting frameworks, serving to streamline reporting processes, enhance data usability, and ensure compliance with regulatory requirements. By providing a standardized framework for conveying binary and structured information, these elements enhance the clarity, accuracy, and comparability of financial and sustainability disclosures .
Key takeaways
Hopefully, this post has explained all you need to know about enumerations and Booleans as used in the new sustainability disclosures. In practical terms, these are things you can do to use them to the best advantage:
- Tagging software should be aware of the different types of enumerations and Booleans and help users to apply them correctly.
- Taxonomy navigation software should help users identify the list of possible enumeration values.
- Preparers should ensure they understand what they are reporting when they make selections for enumerations and Booleans.
- Analysis tools should make use of these enumerations and Booleans for their intended purpose – to help users search and filter reports.
Related guidance:
How to define a list of allowed values | XBRL
[1] Definition from ISSB IFRS Accounting Taxonomy Update 2: Boolean elements—these allow an entity to choose only ‘true’ or ‘false’ (‘yes’ or ‘no’)
[2] Definition from EFRAG: the Boolean corresponds to a ‘yes’ or ‘no’ (true or false) answer.
[3] 6-gri-sustainability-taxonomy-architecture-and-implementation-guide-final-for-public-consultation-11062024.pdf (globalreporting.org), p.24.
[4] Definition from iXBRL Glossary from XBRL International: Enumerations are a taxonomy-defined ordered list of values for a fact. When a concept is defined to be an enumeration type, then the preparer can only report value(s) from this list. For more information, see the enumerations in XBRL guidance.
[5] Definition from ISSB IFRS Accounting Taxonomy Update 2: “Extensible enumerations—these allow an entity to choose an option from a list (and create an entityspecific option(s) if needed), for example, whether investment in an associate is measured using the equity method or at fair value (‘Equity method’ / ‘At fair value’). There are two variants of extensible enumeration elements—set-valued extensible enumerations and single-valued extensible enumerations. Set-valued extensible enumerations allow an entity to choose more than one option from a specified list, whereas single-valued extensible enumerations allow an entity to choose only one option from a specified”.
[6] Definition from EFRAG: “35. The Boolean types (yes/no) and the enumeration item types (drop-down values) are called semi-narratives (or categorical) hereafter, because they can enrich the unstructured narrative disclosures
40 Glossary. Semi-narrative The Boolean item types (yes/no) and the enumeration item types (see above) are called semi-narratives, because it can enrich the unstructured narrative disclosures. Also called categorical elements”.
[7] 6-gri-sustainability-taxonomy-architecture-and-implementation-guide-final-for-public-consultation-11062024.pdf (globalreporting.org) p.23
