ETSI EG 204 061 V1.1.1 (2025-10)

ETSI GUIDE
Human Factors (HF);
ETSI Accessibility Strategy;
Accessibility of ETSI Deliverables and Improvement
of the Development Process of Deliverables

2 ETSI EG 204 061 V1.1.1 (2025-10)

Reference
DEG/HF-00301566
Keywords
accessibility, usability
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3 ETSI EG 204 061 V1.1.1 (2025-10)
Contents
Intellectual Property Rights . 5
Foreword. 5
Modal verbs terminology . 6
Executive summary . 6
Introduction . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definition of terms, symbols and abbreviations . 8
3.1 Terms . 8
3.2 Symbols . 9
3.3 Abbreviations . 9
4 Basic assumptions . 9
4.1 Characteristics and abilities of users and content creators of ETSI deliverables . 9
5 Important recommendations to enhance the accessibility of ETSI deliverables . 10
5.1 Overview . 10
5.2 Recommendations and Guidelines . 11
5.2.1 Colour. 11
5.2.2 Missing alt text . 13
5.2.3 Diagrams / Pictures . 13
5.2.4 Tables . 15
5.2.5 Text properties and coding . 17
5.2.6 References . 19
5.2.7 Acronyms and capitalized text . 20
5.2.8 Document properties . 22
6 Authors'/content creators' requirements with respect to the accessibility of ETSI deliverables and
the development process of accessible documents . 23
6.1 Overview . 23
6.2 Requirements of authors/content creators of ETSI deliverables . 23
6.2.1 Introduction . 23
6.2.2 Requirements on instructions and training . 23
6.2.3 Requirements related to tools for creating accessible deliverables . 24
6.2.4 Requirements on the editing/publishing processes . 25
6.2.5 Concluding remarks . 25
6.3 SDOs and their approach to creating accessible standards documents . 26
6.3.1 General . 26
6.3.2 CEN/CENELEC . 26
6.3.3 DIN. 26
6.3.4 ITU . 26
6.3.5 IEEE . 27
6.3.6 IEC . 27
6.3.7 Canadian Standards Organization (Accessibility Standards Canada) . 27
6.3.8 ACM. 27
6.3.9 Concluding Remarks . 27
7 User-centred analysis of the accessibility and usability of ETSI deliverables . 28
7.1 Overview . 28
7.2 Requirements of blind users and those with low vision . 28
7.2.1 General . 28
7.2.2 Requirements. 28
7.3 Requirements of deaf users and those with hearing impairments . 30
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4 ETSI EG 204 061 V1.1.1 (2025-10)
7.3.1 General . 30
7.3.2 Requirements. 31
7.4 Requirements of mobility-impaired users . 31
7.4.1 General . 31
7.4.2 Requirements. 31
7.5 Requirements of users with cognitive or intellectual disabilities . 32
7.5.1 General . 32
7.5.2 Requirements. 32
7.6 Requirements of users with multiple impairments . 32
8 Recommendations for accessible and usable ETSI deliverables and solution proposals to
implement these recommendations . 33
8.1 Overview . 33
st
8.2 Proposals and solutions - 1 phase . 33
8.2.1 Content creation by authors . 33
8.2.2 Document preparation by ETSI . 35
8.2.3 Document production by ETSI. 36
nd
8.3 Recommendations for implementation - 2 phase . 37
8.3.1 Content creation by authors . 37
8.3.2 Document preparation by ETSI . 37
8.3.3 Document production by ETSI. 38
rd
8.4 Proposals for implementation - 3 phase . 38
8.4.1 Introduction . 38
8.4.2 Document creation by authors . 39
8.4.3 Tools for the Development of Specific Content . 41
8.4.4 (Semi-) Automatic creation of document-internal references . 41
8.4.5 Using alternative formats to make long ETSI Deliverable accessible . 41
8.4.6 Provision of alternative document formats and additional background information in the ETSI
standards repository . 42
Annex A: List of available markdown tools . 43
Annex B: Bibliography . 44
History . 45

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5 ETSI EG 204 061 V1.1.1 (2025-10)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its
Members. 3GPP™, LTE™ and 5G™ logo are trademarks of ETSI registered for the benefit of its Members and of the
3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Foreword
This ETSI Guide (EG) has been produced by ETSI Technical Committee Human Factors (HF).
It is a contribution to the implementation of ETSI's Accessibility Strategy as endorsed by ETSI's General
Assembly #81. The Accessibility Strategy calls for four projects to be carried out with the aim of making ETSI's
products, environment, and meetings accessible to users and participants with a wide range of characteristics.
The objectives of these projects are to:
1) Review the accessibility of ETSI infrastructure (buildings, facilities); Define baseline requirements and
guidelines.
2) Make ETSI published deliverables accessible, including improvement of their development process.
3) Make ETSI meetings accessible on demand, including online and hybrid meetings.
4) Make IT processes and tools accessible, possibly starting with an audit and recommendations for the future.
The present document reports the results of the second of the four projects, providing solutions that enable ETSI to
publish accessible documents.
The work carried out for the creation of the present document has been conducted in an open collaboration with ETSI
members (including authors of ETSI deliverables), user and accessibility representatives, and other relevant
stakeholders. The present document is based upon desk research (documents and online sources), best practices, expert
knowledge, and stakeholder consultation.
Intended readers of the present document include, but are not limited to:
• ETSI Technical Committee members including committee chairs;
• authors of documents published by ETSI;
• ETSI personnel involved in document processing and publishing.
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6 ETSI EG 204 061 V1.1.1 (2025-10)
Modal verbs terminology
In the present document "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be
interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Executive summary
The present document addresses the accessibility of ETSI deliverables for users with physical and/or cognitive
disabilities. It contains recommendations that are based on the consultation of different sources:
• Expert judgement for the identification of improvements that are easily implemented and that can immediately
improve the accessibility of ETSI deliverables (clause 5).
• Consultation of authors of ETSI deliverables with a focus on their requirements related to the creation of
content for accessible deliverables (clause 6).
• Consultation of users of ETSI deliverables who have physical and/or cognitive disabilities (clause 7).
The results of the analysis are summed up in clause 8 in the form of a comprehensive set of guidelines
recommendations to ensure accessible and usable ETSI deliverables, including recommendations for the needed
modifications of the ETSI publication processes and specifications of most suitable tools for publication.
Introduction
The currently implemented processes for drafting, creating, and publishing ETSI deliverables are stable and
state-of-the-art, and have allowed ETSI over the last decades to publish high-quality deliverables satisfying all quality
criteria applicable to international standardization publications.
The one aspect in which ETSI deliverables (and those of all other standards bodies) may fall short is the accessibility of
the deliverables, i.e. aspects of ETSI deliverables that make it difficult or impossible for people with physical or
cognitive disabilities to use them.
The present document explores options to make ETSI deliverables fully accessible for users with disabilities. Based on
expert judgement as well as on the consultation of both content creators of ETSI deliverables and of users with
disabilities, the guidelines and recommendations offer many options to ensuring the accessibility of ETSI deliverables.

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7 ETSI EG 204 061 V1.1.1 (2025-10)
1 Scope
The present document addresses the accessibility of ETSI deliverables for users with physical and/or cognitive
disabilities. It contains recommendations that are based on the consultation of different sources: expert judgement for
the identification of improvements that are easily implemented and that can immediately improve the accessibility of
ETSI deliverables, the consultation of authors of ETSI deliverables with a focus on their requirements related to the
creation of content for accessible deliverables, and the consultation of users of ETSI deliverables who have physical
and/or cognitive disabilities.
The results of the analysis take the form of a comprehensive set of recommendations and guidelines to ensure accessible
and usable ETSI deliverables, including recommendations for the needed modifications of the ETSI publication
processes and specifications of most suitable tools for publication. For this task, short-term, mid-term and, long-term
perspectives have been adopted, ranging from immediate changes to a strategic outlook of a future publication
environment of ETSI deliverables.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
The following referenced documents may be useful in implementing an ETSI deliverable or add to the reader's
understanding, but are not required for conformance to the present document.
[i.1] ETSI EG 201 013: "Human Factors (HF); Definitions, abbreviations and symbols".
[i.2] ISO 26800:2011: "Ergonomics — General approach, principles and concepts". ®
[i.3] W3C Recommendation (December 2024): "Web Content Accessibility Guidelines (WCAG) 2.2".
®:
[i.4] W3C "Guidance on Applying WCAG 2 to Non-Web Information and Communications
Technologies (WCAG2ICT)".
[i.5] Yale University: "Usability & Web Accessibility: Types of Disabilities".
[i.6] ISO 32000-1:2008: "Document management — Portable document format".
[i.7] ETSI EN 301 549 (V3.2.1): "Accessibility requirements for ICT products and services" (jointly
produced by ETSI/CEN/CENELEC).
[i.8] CAN/ASC - EN 301 549:2024: "Accessibility requirements for ICT products and services
(ETSI EN 301 549:2021, IDT)".
[i.9] ISO/IEC SMART: "Unleashing the digital power of international standards".
[i.10] Directive (EU) 2019/882 of the European Parliament and of the Council of 17 April 2019 on the
accessibility requirements for products and services (Text with EEA relevance).
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8 ETSI EG 204 061 V1.1.1 (2025-10)
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in ETSI EG 201 013 [i.1] and the following apply:
accessibility: extent to which products, systems, services, environments and facilities can be used by people from a
population with the widest range of characteristics and capabilities, to achieve a specified goal in a specified context of
use
NOTE 1: Context of use includes direct use or use supported by assistive technologies.
NOTE 2: The context in which the ICT is used may affect its overall accessibility. This context could include other
products and services with which the ICT may interact.
NOTE 3: As defined in ISO 26800 [i.2].
assistive technology: hardware or software added to or connected to a system that increases accessibility for an
individual
NOTE 1: Examples are Braille displays, screen readers, screen magnification software and eye tracking devices that
are added to the ICT.
NOTE 2: Where ICT does not support directly connected assistive technology, but which can be operated by a
system connected over a network or other remote connection, such a separate system (with any included
assistive technology) can also be considered assistive technology.
caption: synchronized visual and/or text alternative for both speech and non-speech audio information needed to
understand the media content
NOTE 1: This is also variously described using terms such as "subtitles" or variants such as "subtitles for the deaf
and hard-of-hearing".
NOTE 2: As defined in WCAG 2.2 [i.3]
content: information and sensory experience to be communicated to the user by means of software, including code or
markup that defines the content's structure, presentation, and interactions
NOTE 1: Content occurs in three places: web pages, documents and software. When content occurs in a web page
or a document, a user agent is needed in order to communicate the content's information and sensory
experience to the user. When content occurs in software, a separate user agent is not needed in order to
communicate the content's information and sensory experience to the user - the software itself performs
that function.
NOTE 2: As defined in WCAG2ICT [i.4].
document: logically distinct assembly of content (such as a file, set of files, or streamed media) that functions as a
single entity rather than a collection, that is not part of software and that does not include its own user agent
NOTE 1: Letters, email messages, spreadsheets, books, pictures, presentations, and movies are examples of
documents.
NOTE 2: A single document may be composed of multiple files such as the video content, closed caption text etc.
This fact is not usually apparent to the end-user consuming the document/content.
NOTE 3: As defined in WCAG2ICT [i.4].
markdown: lightweight markup language for creating formatted text using a plain-text editor
web content: content that belongs to a web page, and that is used in the rendering or that is intended to be used in the
rendering of the web page
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9 ETSI EG 204 061 V1.1.1 (2025-10)
web page: non-embedded resource obtained from a single URI using HTTP plus any other resources that are used in
the rendering or intended to be rendered together with it by a user agent
NOTE: As defined in WCAG 2.2 [i.3].
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACM Association of Computing Machinery
ADHD Attention Deficit Hyperactivity Disorder
ASC Accessibility Standards Canada
CCMC CEN/CENELEC Management Centre
CEN/CENELEC European Committee for Standardization/European Committee for Electrotechnical
Standardization
DIN Deutsches Institut für Normung
HTML HyperText Markup Language
HTTP HyperText Transfer Protocol
ICT Information and Communication Technologies
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronics Engineers
ISO International Organization for Standardization
ITU International Telecommunication Union
JSON JavaScript Object Notation
NSB National Standards Body
NSO National Standards Organization
OCR Optical Character Recognition
PDF Portable Document Format
PDF/A PDF Archivable
PDF/UA PDF Universal Accessibility
RDF Resource Description Framework
SDO Standards Development Organization
TIES Telecommunication Information Exchange Service
NOTE: An ITU service, offering access to ITU standards for ITU members.
UML Unified Modeling Language
WCAG Web Content Accessibility Guidelines
XML Extensible Markup Language
4 Basic assumptions
4.1 Characteristics and abilities of users and content creators of
ETSI deliverables
Unless ETSI deliverables are developed and made available in an accessible format, they may present challenges to
users and content creators with physical, sensory, or cognitive impairments.
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Users and/or creators of ETSI deliverables may be experiencing varying degrees or combinations of visual, auditory,
physical, speech or cognitive impairments (for more details see e.g. Usability and Web Accessibility: Types of
Disabilities [i.5]):
• visual impairments: including any form of colour blindness, low vision, and blindness (substantial loss of
vision in both eyes);
• auditory impairments: including mild to moderate hearing impairments in at least one ear up to deafness
(hearing impairment that is substantial and non-correctable in both ears);
• physical impairments: including amputation (e.g. missing digits or limbs), arthritis (inflammation and damage
to joints), paralysis (loss of control over a limb or other part of the body), and Repetitive Stress Injury;
• speech impairments: including muteness (the inability to speak due to a multitude of reasons), dysarthria
(weakness or paralysis of the muscles required to speak), and stuttering; and
• cognitive, learning, and neurological impairments: including Attention Deficit Hyperactivity Disorder
(ADHD), autism spectrum disorder, perceptual disabilities (also called "learning disabilities" such as dyslexia
and dyscalculia), and seizure disorders.
The impairments may be due to a persistent health condition, being in-born or a result of illness or accident. But they
may also be due to a temporary condition incurred by a short-term health condition (like a broken arm), or by current
situational circumstances including specific environmental conditions, such as a very bright light or a very noisy
environment, or other circumstances, like lack of access to specific technologies resulting in the need to access a
document on a device with a smaller screen.
In all cases, it is assumed that users/creators who have any individual impairment or a combination thereof, deploy
suitable assistive technologies to access digital documents.
NOTE 1: Users/creators of ETSI deliverables are expected to be able to understand written language.
NOTE 2: ETSI deliverables are written and published in English language. Users/creators of ETSI deliverables are
expected to either have a sufficient command of the English language and/or have access to tools that
represents the content of ETSI deliverables in a language they understand.
NOTE 3: Users/creators of ETSI deliverables are expected to have a relevant educational background, e.g. in the
specific engineering domain of a given deliverable.
5 Important recommendations to enhance the
accessibility of ETSI deliverables
5.1 Overview
The recommendations and guidelines presented in this clause are based on the evaluation of several ETSI deliverables
representing a range of document types. Those documents were evaluated (a) against a set of criteria extracted from
EN 301 549 [i.7] and (b) against a set of testing tools for the accessibility of Microsoft Word and PDF files (the tools
included Microsoft Word, Adobe Acrobat Pro and PDF accessibility checkers available as freeware).
This clause lists the accessibility issues found in the ETSI deliverables tested (in the document formats currently used
by ETSI, i.e. Word and PDF). For each of the issues identified recommendations (guidelines) are presented on how to
either resolve these issues in existing documents or to avoid these accessibility issues in future documents.
This clause contains guidelines which will help to make ETSI deliverables more accessible. These guidelines may be
applied both to existing documents and to deliverables which are developed in the future.
The list of accessibility issues in this clause is by no means exhaustive as more issues may be identified in the future.
Many of the guidelines explain "low-hanging fruits". Both the ETSI Secretariat and the authors of documents can use
them to ensure accessibility of their deliverables with reasonable additional effort. Many of these guidelines may be
treated in future updates of the ETSI Drafting Rules or in a separate publication on accessibility.
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11 ETSI EG 204 061 V1.1.1 (2025-10)
These guidelines presented in this clause fall into three categories:
1) Recommendations for measures to apply in order to guarantee the maximum degree of accessibility of
documents when issuing (e.g. upon request) accessible documents previously published. These
recommendations are mainly directed at the ETSI Secretariat which may have to contact document authors in
some cases.
2) Recommendations for changes to be made to the document templates in order to minimize accessibility issues.
3) Recommendations for authors: these are instructions to authors of measures to apply in order to minimize
accessibility problems for users (e.g. use of colours, alternative text for images, etc.). These may be added by
ETSI in a future revision of the ETSI Drafting Rules or in a separate publication on accessibility. In the
following text, "ETSI" is used to denominate the "ETSI Secretariat".
NOTE 1: The responsibility for creating accessible content lies with the authors of that content, i.e. while it is
ETSI's 'task to identify content that is not accessible, it is not their task to fix this. Instead, they should
return the document to the authors with a pointer to the problem(s) identified and proposed solutions.
NOTE 2: ETSI intends to provide guidance to authors on the recommendations listed in clause 5.2. This should
cover what is being expected from authors and how they can apply these recommendations. Options for
providing this guidance are to express them in a revision of the ETSI Drafting Rules, or to release them as
a separate publication made available to authors.
5.2 Recommendations and Guidelines
5.2.1 Colour
5.2.1.1 Contrast
Accessibility Issue
Low contrast between text and surrounding background in pictures or diagrams.
Explanation
If text in pictures or diagrams is necessary for the interpretation of the picture, text and background should have a
contrast ratio of at least 4.5:1, or 3:1 for large text.
Guidelines for authors
• For each picture in a deliverable, authors should perform the following checks and actions:
- If a picture or diagram contains text or text images, check the contrast ratio between text and background
using publicly available contrast checker tools (e.g. Colour Contrast Analyser). If the contrast ratio
minimum is not met, modify the picture/surrounding in a way that the contrast ratio gets enhanced.
- If the contrast ratio minimum cannot be met by colour modifications, change the picture or part of the
picture to black and white presentation.
Background Information / References
Covered in EN 301 549 [i.7], clause 10.1.4.3, and WCAG Success Criterion 4.1.3 ((WCAG) 2.2 [i.3]).
5.2.1.2 Colour combinations
Accessibility Issue
Certain colour combinations (e.g. yellow/purple and black/red, etc.) may cause problems with blurs for people with
reduced eyesight. Also, colour blindness may cause certain colour combinations to not be interpreted correctly.
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12 ETSI EG 204 061 V1.1.1 (2025-10)
Explanation
Combinations of certain colours either cause lines to be blurred or may be difficult to be interpreted by people with
colour blindness.
Guidelines for authors
• Authors should avoid too stark colour contrasts (e.g. yellow/purple or black/red,) as this may cause blurred
lines on displays.
• Authors should avoid colour combinations like blue/yellow or red/green as these may be seen as grey shades
only by readers who are colour blind.
5.2.1.3 Colour coding / use of colour
Accessibility Issue
Colour should not be used as the only visual means to convey meaning in a document.
For example, diagrams may encapsulate a colour code to represent specific elements based on their context. This aspect
increases the difficulty of reading the document by accessibility tools used by people affected by visual or cognitive
impairments.
Explanation
If colour is used (in formatting text or in pictures) to convey a special interpretation of the displayed content, this
interpretation may be lost to colour-blind people or users of screen readers or of documents printed on a monochrome
printer. Therefore, the interpretation of the colour should be conveyed by other means (e.g. alt text, colour plus
hatching, other font properties, or textual explanations).
It is a recognized usability requirement that colour should never be used as the only means for encoding a certain type
of information. For example, data expressed in a bar diagram can be displayed in bars of different colours, provided that
(a) those colours are appearing discernibly different when displayed/printed in grey tones and (b) the information is also
presented when the user requires information about a specific element (e.g. using mouse over or a screen reader).
Patterns (dots, hatching lines) can be used in addition to colours.
Guidelines for authors
• Authors should either decide not to express information in colour or ensure that colour is never the only means
for expressing information.
• If colours are used in pictures or graphs, the colour coding should be explained in alt text.
• If colours are used to convey meaning in running text, other coding means (bold face, italics, other font sizes)
should be used in addition to the colour code.
• If colours are used to convey meaning in a running text, the colour code should be explained at the beginning
of the text section (or as alt text, if possible).
• Authors should provide a description of the colouring conventions used in each diagram included in a
document.
• Authors should provide an equivalent textual representation of the diagram's content to enhance the
comprehensiveness of the document and to enable accessibility tools to provide all information to the reader.
Guidelines for ETSI
• ETSI should provide guidelines about the use of colours in ETSI deliverables (this applies to text, graphics,
tables, and any other means for expressing information).
• ETSI should check that each diagram contained in ETSI deliverables has an equivalent description of its
content.
• ETSI should check that possible implicit conventions used by the authors are explained in the document.
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13 ETSI EG 204 061 V1.1.1 (2025-10)
Background Information / References
Covered in EN 301 549 [i.7], clause 10.1.3.1.
Covered in EN 301 549 [i.7], clauses 9.1.4.1 and 10.1.4.1, and WCAG Success Criterion 1.4.1 Use of Colour
(WCAG 2.2 [i.3]).
Covered in EN 301 549 [i.7], clauses 9.1.1.1 and 10.1.1.1, and WCAG Success Criterion 1.1.1 Non-text Content
(WCAG) 2.2 [i.3]).
5.2.2 Missing alt text
Accessibility Issue
For tables, pictures, formulae, and other specially formatted content ("Non-text Content"), which may be difficult or
impossible to assess by people with limited eyesight or by the users of screen readers, an alternative textual description
(alt text) should be attached to the Non-text Content.
Explanation
If a document contains pictures, formulae, tables or other content not formatted as running text (Non-text Content), the
users of screen readers or readers with very limited eyesight may not be able to correctly interpret the content of these
sections. For these users, an alternative text-based explanation of the Non-text Content should be made available (alt
text).
Guidelines for authors
• Authors should provide for each picture, table, formulae or other non-text content an alt text description.
Guidelines for ETSI
• ETSI should check that for each picture, table, formulae or other non-text content an alt text description is
available.
Background Information / References
Covered in EN 301 549 [i.7], clauses 9.1.1.1 and 10.1.1.1, and WCAG Success Criterion 1.1.1 Non-text Content
(WCAG 2.2 [i.3]).
5.2.3 Diagrams / Pictures
5.2.3.1 Machine-readable text
Accessibility Issue
A picture or graph should not contain text in binary form, if that text is relevant for the interpretation of the content.
Explanation
Text in binary format is usually not accessible to screen readers. For screen reader users the text should either be
changed to machine-interpretable text (OCR), or the contents should be explained in the alt text.
Guidelines for authors
• Authors should mention in alt text if a picture or graph contains text that is only decorative.
• If a picture or graph contains binary representations of text that is needed for the interpretation of the graph or
the document contents, authors should extract the binary text and apply OCR.
• Authors should replace the binary representation of text with the text extracted by the OCR.
• Authors should explain the contents of text presented in binary format in alt text, if integrating OCR-ed
content is not possible.
ETSI
14 ETSI EG 204 061 V1.1.1 (2025-10)
Background Information / References
Covered in EN 301 549 [i.7], clauses 9.1.4.5 and 10.1.4.5, and WCAG Success Criterion 1.4.5 Images of Text
(WCAG 2.2 [i.3]).
5.2.3.2 Large amount of text in figures
Accessibility Issue
Pictures containing large amounts of text may cause problems for assistive technologies and should be avoided.
Explanation
If large amounts of text are contained in pictures which may not be subject to reformatting, accessibility tools like
screen readers may run into problems when trying to display the contents of a picture. Also, trying to enlarge the picture
may lead to unusable pictures requiring scrolling.
Large amounts of text in pictures should therefore be avoided.
Guidelines for authors
• If a picture or graph contains a lot of text, authors should try to move the text to the figure header or add it as a
note right below the figure.
• If that is not possible, authors should explain the contents of the relevant text sections in the alt text of the
figure or in a paragraph of text following the picture.
Background Information / References
This is primarily a usability issue but also relevant for assistive technology.
5.2.3.3 Diagrams developed with tools which do not capture semantic
...

SLOVENSKI STANDARD
01-januar-2026
Človeški dejavniki (HF) - Strategija dostopnosti ETSI - Dostopnost dokumentov
ETSI in izboljšanje postopka njihovega pripravljanja
Human Factors (HF) - ETSI Accessibility Strategy - Accessibility of ETSI Deliverables
and Improvement of the Development Process of Deliverables
Ta slovenski standard je istoveten z: ETSI EG 204 061 V1.1.1 (2025-10)
ICS:
33.040.01 Telekomunikacijski sistemi Telecommunication systems
na splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETSI GUIDE
Human Factors (HF);
ETSI Accessibility Strategy;
Accessibility of ETSI Deliverables and Improvement
of the Development Process of Deliverables

2 ETSI EG 204 061 V1.1.1 (2025-10)

Reference
DEG/HF-00301566
Keywords
accessibility, usability
ETSI
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ETSI
3 ETSI EG 204 061 V1.1.1 (2025-10)
Contents
Intellectual Property Rights . 5
Foreword. 5
Modal verbs terminology . 6
Executive summary . 6
Introduction . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definition of terms, symbols and abbreviations . 8
3.1 Terms . 8
3.2 Symbols . 9
3.3 Abbreviations . 9
4 Basic assumptions . 9
4.1 Characteristics and abilities of users and content creators of ETSI deliverables . 9
5 Important recommendations to enhance the accessibility of ETSI deliverables . 10
5.1 Overview . 10
5.2 Recommendations and Guidelines . 11
5.2.1 Colour. 11
5.2.2 Missing alt text . 13
5.2.3 Diagrams / Pictures . 13
5.2.4 Tables . 15
5.2.5 Text properties and coding . 17
5.2.6 References . 19
5.2.7 Acronyms and capitalized text . 20
5.2.8 Document properties . 22
6 Authors'/content creators' requirements with respect to the accessibility of ETSI deliverables and
the development process of accessible documents . 23
6.1 Overview . 23
6.2 Requirements of authors/content creators of ETSI deliverables . 23
6.2.1 Introduction . 23
6.2.2 Requirements on instructions and training . 23
6.2.3 Requirements related to tools for creating accessible deliverables . 24
6.2.4 Requirements on the editing/publishing processes . 25
6.2.5 Concluding remarks . 25
6.3 SDOs and their approach to creating accessible standards documents . 26
6.3.1 General . 26
6.3.2 CEN/CENELEC . 26
6.3.3 DIN. 26
6.3.4 ITU . 26
6.3.5 IEEE . 27
6.3.6 IEC . 27
6.3.7 Canadian Standards Organization (Accessibility Standards Canada) . 27
6.3.8 ACM. 27
6.3.9 Concluding Remarks . 27
7 User-centred analysis of the accessibility and usability of ETSI deliverables . 28
7.1 Overview . 28
7.2 Requirements of blind users and those with low vision . 28
7.2.1 General . 28
7.2.2 Requirements. 28
7.3 Requirements of deaf users and those with hearing impairments . 30
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4 ETSI EG 204 061 V1.1.1 (2025-10)
7.3.1 General . 30
7.3.2 Requirements. 31
7.4 Requirements of mobility-impaired users . 31
7.4.1 General . 31
7.4.2 Requirements. 31
7.5 Requirements of users with cognitive or intellectual disabilities . 32
7.5.1 General . 32
7.5.2 Requirements. 32
7.6 Requirements of users with multiple impairments . 32
8 Recommendations for accessible and usable ETSI deliverables and solution proposals to
implement these recommendations . 33
8.1 Overview . 33
st
8.2 Proposals and solutions - 1 phase . 33
8.2.1 Content creation by authors . 33
8.2.2 Document preparation by ETSI . 35
8.2.3 Document production by ETSI. 36
nd
8.3 Recommendations for implementation - 2 phase . 37
8.3.1 Content creation by authors . 37
8.3.2 Document preparation by ETSI . 37
8.3.3 Document production by ETSI. 38
rd
8.4 Proposals for implementation - 3 phase . 38
8.4.1 Introduction . 38
8.4.2 Document creation by authors . 39
8.4.3 Tools for the Development of Specific Content . 41
8.4.4 (Semi-) Automatic creation of document-internal references . 41
8.4.5 Using alternative formats to make long ETSI Deliverable accessible . 41
8.4.6 Provision of alternative document formats and additional background information in the ETSI
standards repository . 42
Annex A: List of available markdown tools . 43
Annex B: Bibliography . 44
History . 45

ETSI
5 ETSI EG 204 061 V1.1.1 (2025-10)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its
Members. 3GPP™, LTE™ and 5G™ logo are trademarks of ETSI registered for the benefit of its Members and of the
3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Foreword
This ETSI Guide (EG) has been produced by ETSI Technical Committee Human Factors (HF).
It is a contribution to the implementation of ETSI's Accessibility Strategy as endorsed by ETSI's General
Assembly #81. The Accessibility Strategy calls for four projects to be carried out with the aim of making ETSI's
products, environment, and meetings accessible to users and participants with a wide range of characteristics.
The objectives of these projects are to:
1) Review the accessibility of ETSI infrastructure (buildings, facilities); Define baseline requirements and
guidelines.
2) Make ETSI published deliverables accessible, including improvement of their development process.
3) Make ETSI meetings accessible on demand, including online and hybrid meetings.
4) Make IT processes and tools accessible, possibly starting with an audit and recommendations for the future.
The present document reports the results of the second of the four projects, providing solutions that enable ETSI to
publish accessible documents.
The work carried out for the creation of the present document has been conducted in an open collaboration with ETSI
members (including authors of ETSI deliverables), user and accessibility representatives, and other relevant
stakeholders. The present document is based upon desk research (documents and online sources), best practices, expert
knowledge, and stakeholder consultation.
Intended readers of the present document include, but are not limited to:
• ETSI Technical Committee members including committee chairs;
• authors of documents published by ETSI;
• ETSI personnel involved in document processing and publishing.
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6 ETSI EG 204 061 V1.1.1 (2025-10)
Modal verbs terminology
In the present document "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be
interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Executive summary
The present document addresses the accessibility of ETSI deliverables for users with physical and/or cognitive
disabilities. It contains recommendations that are based on the consultation of different sources:
• Expert judgement for the identification of improvements that are easily implemented and that can immediately
improve the accessibility of ETSI deliverables (clause 5).
• Consultation of authors of ETSI deliverables with a focus on their requirements related to the creation of
content for accessible deliverables (clause 6).
• Consultation of users of ETSI deliverables who have physical and/or cognitive disabilities (clause 7).
The results of the analysis are summed up in clause 8 in the form of a comprehensive set of guidelines
recommendations to ensure accessible and usable ETSI deliverables, including recommendations for the needed
modifications of the ETSI publication processes and specifications of most suitable tools for publication.
Introduction
The currently implemented processes for drafting, creating, and publishing ETSI deliverables are stable and
state-of-the-art, and have allowed ETSI over the last decades to publish high-quality deliverables satisfying all quality
criteria applicable to international standardization publications.
The one aspect in which ETSI deliverables (and those of all other standards bodies) may fall short is the accessibility of
the deliverables, i.e. aspects of ETSI deliverables that make it difficult or impossible for people with physical or
cognitive disabilities to use them.
The present document explores options to make ETSI deliverables fully accessible for users with disabilities. Based on
expert judgement as well as on the consultation of both content creators of ETSI deliverables and of users with
disabilities, the guidelines and recommendations offer many options to ensuring the accessibility of ETSI deliverables.

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7 ETSI EG 204 061 V1.1.1 (2025-10)
1 Scope
The present document addresses the accessibility of ETSI deliverables for users with physical and/or cognitive
disabilities. It contains recommendations that are based on the consultation of different sources: expert judgement for
the identification of improvements that are easily implemented and that can immediately improve the accessibility of
ETSI deliverables, the consultation of authors of ETSI deliverables with a focus on their requirements related to the
creation of content for accessible deliverables, and the consultation of users of ETSI deliverables who have physical
and/or cognitive disabilities.
The results of the analysis take the form of a comprehensive set of recommendations and guidelines to ensure accessible
and usable ETSI deliverables, including recommendations for the needed modifications of the ETSI publication
processes and specifications of most suitable tools for publication. For this task, short-term, mid-term and, long-term
perspectives have been adopted, ranging from immediate changes to a strategic outlook of a future publication
environment of ETSI deliverables.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
The following referenced documents may be useful in implementing an ETSI deliverable or add to the reader's
understanding, but are not required for conformance to the present document.
[i.1] ETSI EG 201 013: "Human Factors (HF); Definitions, abbreviations and symbols".
[i.2] ISO 26800:2011: "Ergonomics — General approach, principles and concepts". ®
[i.3] W3C Recommendation (December 2024): "Web Content Accessibility Guidelines (WCAG) 2.2".
®:
[i.4] W3C "Guidance on Applying WCAG 2 to Non-Web Information and Communications
Technologies (WCAG2ICT)".
[i.5] Yale University: "Usability & Web Accessibility: Types of Disabilities".
[i.6] ISO 32000-1:2008: "Document management — Portable document format".
[i.7] ETSI EN 301 549 (V3.2.1): "Accessibility requirements for ICT products and services" (jointly
produced by ETSI/CEN/CENELEC).
[i.8] CAN/ASC - EN 301 549:2024: "Accessibility requirements for ICT products and services
(ETSI EN 301 549:2021, IDT)".
[i.9] ISO/IEC SMART: "Unleashing the digital power of international standards".
[i.10] Directive (EU) 2019/882 of the European Parliament and of the Council of 17 April 2019 on the
accessibility requirements for products and services (Text with EEA relevance).
ETSI
8 ETSI EG 204 061 V1.1.1 (2025-10)
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in ETSI EG 201 013 [i.1] and the following apply:
accessibility: extent to which products, systems, services, environments and facilities can be used by people from a
population with the widest range of characteristics and capabilities, to achieve a specified goal in a specified context of
use
NOTE 1: Context of use includes direct use or use supported by assistive technologies.
NOTE 2: The context in which the ICT is used may affect its overall accessibility. This context could include other
products and services with which the ICT may interact.
NOTE 3: As defined in ISO 26800 [i.2].
assistive technology: hardware or software added to or connected to a system that increases accessibility for an
individual
NOTE 1: Examples are Braille displays, screen readers, screen magnification software and eye tracking devices that
are added to the ICT.
NOTE 2: Where ICT does not support directly connected assistive technology, but which can be operated by a
system connected over a network or other remote connection, such a separate system (with any included
assistive technology) can also be considered assistive technology.
caption: synchronized visual and/or text alternative for both speech and non-speech audio information needed to
understand the media content
NOTE 1: This is also variously described using terms such as "subtitles" or variants such as "subtitles for the deaf
and hard-of-hearing".
NOTE 2: As defined in WCAG 2.2 [i.3]
content: information and sensory experience to be communicated to the user by means of software, including code or
markup that defines the content's structure, presentation, and interactions
NOTE 1: Content occurs in three places: web pages, documents and software. When content occurs in a web page
or a document, a user agent is needed in order to communicate the content's information and sensory
experience to the user. When content occurs in software, a separate user agent is not needed in order to
communicate the content's information and sensory experience to the user - the software itself performs
that function.
NOTE 2: As defined in WCAG2ICT [i.4].
document: logically distinct assembly of content (such as a file, set of files, or streamed media) that functions as a
single entity rather than a collection, that is not part of software and that does not include its own user agent
NOTE 1: Letters, email messages, spreadsheets, books, pictures, presentations, and movies are examples of
documents.
NOTE 2: A single document may be composed of multiple files such as the video content, closed caption text etc.
This fact is not usually apparent to the end-user consuming the document/content.
NOTE 3: As defined in WCAG2ICT [i.4].
markdown: lightweight markup language for creating formatted text using a plain-text editor
web content: content that belongs to a web page, and that is used in the rendering or that is intended to be used in the
rendering of the web page
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9 ETSI EG 204 061 V1.1.1 (2025-10)
web page: non-embedded resource obtained from a single URI using HTTP plus any other resources that are used in
the rendering or intended to be rendered together with it by a user agent
NOTE: As defined in WCAG 2.2 [i.3].
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACM Association of Computing Machinery
ADHD Attention Deficit Hyperactivity Disorder
ASC Accessibility Standards Canada
CCMC CEN/CENELEC Management Centre
CEN/CENELEC European Committee for Standardization/European Committee for Electrotechnical
Standardization
DIN Deutsches Institut für Normung
HTML HyperText Markup Language
HTTP HyperText Transfer Protocol
ICT Information and Communication Technologies
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronics Engineers
ISO International Organization for Standardization
ITU International Telecommunication Union
JSON JavaScript Object Notation
NSB National Standards Body
NSO National Standards Organization
OCR Optical Character Recognition
PDF Portable Document Format
PDF/A PDF Archivable
PDF/UA PDF Universal Accessibility
RDF Resource Description Framework
SDO Standards Development Organization
TIES Telecommunication Information Exchange Service
NOTE: An ITU service, offering access to ITU standards for ITU members.
UML Unified Modeling Language
WCAG Web Content Accessibility Guidelines
XML Extensible Markup Language
4 Basic assumptions
4.1 Characteristics and abilities of users and content creators of
ETSI deliverables
Unless ETSI deliverables are developed and made available in an accessible format, they may present challenges to
users and content creators with physical, sensory, or cognitive impairments.
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10 ETSI EG 204 061 V1.1.1 (2025-10)
Users and/or creators of ETSI deliverables may be experiencing varying degrees or combinations of visual, auditory,
physical, speech or cognitive impairments (for more details see e.g. Usability and Web Accessibility: Types of
Disabilities [i.5]):
• visual impairments: including any form of colour blindness, low vision, and blindness (substantial loss of
vision in both eyes);
• auditory impairments: including mild to moderate hearing impairments in at least one ear up to deafness
(hearing impairment that is substantial and non-correctable in both ears);
• physical impairments: including amputation (e.g. missing digits or limbs), arthritis (inflammation and damage
to joints), paralysis (loss of control over a limb or other part of the body), and Repetitive Stress Injury;
• speech impairments: including muteness (the inability to speak due to a multitude of reasons), dysarthria
(weakness or paralysis of the muscles required to speak), and stuttering; and
• cognitive, learning, and neurological impairments: including Attention Deficit Hyperactivity Disorder
(ADHD), autism spectrum disorder, perceptual disabilities (also called "learning disabilities" such as dyslexia
and dyscalculia), and seizure disorders.
The impairments may be due to a persistent health condition, being in-born or a result of illness or accident. But they
may also be due to a temporary condition incurred by a short-term health condition (like a broken arm), or by current
situational circumstances including specific environmental conditions, such as a very bright light or a very noisy
environment, or other circumstances, like lack of access to specific technologies resulting in the need to access a
document on a device with a smaller screen.
In all cases, it is assumed that users/creators who have any individual impairment or a combination thereof, deploy
suitable assistive technologies to access digital documents.
NOTE 1: Users/creators of ETSI deliverables are expected to be able to understand written language.
NOTE 2: ETSI deliverables are written and published in English language. Users/creators of ETSI deliverables are
expected to either have a sufficient command of the English language and/or have access to tools that
represents the content of ETSI deliverables in a language they understand.
NOTE 3: Users/creators of ETSI deliverables are expected to have a relevant educational background, e.g. in the
specific engineering domain of a given deliverable.
5 Important recommendations to enhance the
accessibility of ETSI deliverables
5.1 Overview
The recommendations and guidelines presented in this clause are based on the evaluation of several ETSI deliverables
representing a range of document types. Those documents were evaluated (a) against a set of criteria extracted from
EN 301 549 [i.7] and (b) against a set of testing tools for the accessibility of Microsoft Word and PDF files (the tools
included Microsoft Word, Adobe Acrobat Pro and PDF accessibility checkers available as freeware).
This clause lists the accessibility issues found in the ETSI deliverables tested (in the document formats currently used
by ETSI, i.e. Word and PDF). For each of the issues identified recommendations (guidelines) are presented on how to
either resolve these issues in existing documents or to avoid these accessibility issues in future documents.
This clause contains guidelines which will help to make ETSI deliverables more accessible. These guidelines may be
applied both to existing documents and to deliverables which are developed in the future.
The list of accessibility issues in this clause is by no means exhaustive as more issues may be identified in the future.
Many of the guidelines explain "low-hanging fruits". Both the ETSI Secretariat and the authors of documents can use
them to ensure accessibility of their deliverables with reasonable additional effort. Many of these guidelines may be
treated in future updates of the ETSI Drafting Rules or in a separate publication on accessibility.
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11 ETSI EG 204 061 V1.1.1 (2025-10)
These guidelines presented in this clause fall into three categories:
1) Recommendations for measures to apply in order to guarantee the maximum degree of accessibility of
documents when issuing (e.g. upon request) accessible documents previously published. These
recommendations are mainly directed at the ETSI Secretariat which may have to contact document authors in
some cases.
2) Recommendations for changes to be made to the document templates in order to minimize accessibility issues.
3) Recommendations for authors: these are instructions to authors of measures to apply in order to minimize
accessibility problems for users (e.g. use of colours, alternative text for images, etc.). These may be added by
ETSI in a future revision of the ETSI Drafting Rules or in a separate publication on accessibility. In the
following text, "ETSI" is used to denominate the "ETSI Secretariat".
NOTE 1: The responsibility for creating accessible content lies with the authors of that content, i.e. while it is
ETSI's 'task to identify content that is not accessible, it is not their task to fix this. Instead, they should
return the document to the authors with a pointer to the problem(s) identified and proposed solutions.
NOTE 2: ETSI intends to provide guidance to authors on the recommendations listed in clause 5.2. This should
cover what is being expected from authors and how they can apply these recommendations. Options for
providing this guidance are to express them in a revision of the ETSI Drafting Rules, or to release them as
a separate publication made available to authors.
5.2 Recommendations and Guidelines
5.2.1 Colour
5.2.1.1 Contrast
Accessibility Issue
Low contrast between text and surrounding background in pictures or diagrams.
Explanation
If text in pictures or diagrams is necessary for the interpretation of the picture, text and background should have a
contrast ratio of at least 4.5:1, or 3:1 for large text.
Guidelines for authors
• For each picture in a deliverable, authors should perform the following checks and actions:
- If a picture or diagram contains text or text images, check the contrast ratio between text and background
using publicly available contrast checker tools (e.g. Colour Contrast Analyser). If the contrast ratio
minimum is not met, modify the picture/surrounding in a way that the contrast ratio gets enhanced.
- If the contrast ratio minimum cannot be met by colour modifications, change the picture or part of the
picture to black and white presentation.
Background Information / References
Covered in EN 301 549 [i.7], clause 10.1.4.3, and WCAG Success Criterion 4.1.3 ((WCAG) 2.2 [i.3]).
5.2.1.2 Colour combinations
Accessibility Issue
Certain colour combinations (e.g. yellow/purple and black/red, etc.) may cause problems with blurs for people with
reduced eyesight. Also, colour blindness may cause certain colour combinations to not be interpreted correctly.
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12 ETSI EG 204 061 V1.1.1 (2025-10)
Explanation
Combinations of certain colours either cause lines to be blurred or may be difficult to be interpreted by people with
colour blindness.
Guidelines for authors
• Authors should avoid too stark colour contrasts (e.g. yellow/purple or black/red,) as this may cause blurred
lines on displays.
• Authors should avoid colour combinations like blue/yellow or red/green as these may be seen as grey shades
only by readers who are colour blind.
5.2.1.3 Colour coding / use of colour
Accessibility Issue
Colour should not be used as the only visual means to convey meaning in a document.
For example, diagrams may encapsulate a colour code to represent specific elements based on their context. This aspect
increases the difficulty of reading the document by accessibility tools used by people affected by visual or cognitive
impairments.
Explanation
If colour is used (in formatting text or in pictures) to convey a special interpretation of the displayed content, this
interpretation may be lost to colour-blind people or users of screen readers or of documents printed on a monochrome
printer. Therefore, the interpretation of the colour should be conveyed by other means (e.g. alt text, colour plus
hatching, other font properties, or textual explanations).
It is a recognized usability requirement that colour should never be used as the only means for encoding a certain type
of information. For example, data expressed in a bar diagram can be displayed in bars of different colours, provided that
(a) those colours are appearing discernibly different when displayed/printed in grey tones and (b) the information is also
presented when the user requires information about a specific element (e.g. using mouse over or a screen reader).
Patterns (dots, hatching lines) can be used in addition to colours.
Guidelines for authors
• Authors should either decide not to express information in colour or ensure that colour is never the only means
for expressing information.
• If colours are used in pictures or graphs, the colour coding should be explained in alt text.
• If colours are used to convey meaning in running text, other coding means (bold face, italics, other font sizes)
should be used in addition to the colour code.
• If colours are used to convey meaning in a running text, the colour code should be explained at the beginning
of the text section (or as alt text, if possible).
• Authors should provide a description of the colouring conventions used in each diagram included in a
document.
• Authors should provide an equivalent textual representation of the diagram's content to enhance the
comprehensiveness of the document and to enable accessibility tools to provide all information to the reader.
Guidelines for ETSI
• ETSI should provide guidelines about the use of colours in ETSI deliverables (this applies to text, graphics,
tables, and any other means for expressing information).
• ETSI should check that each diagram contained in ETSI deliverables has an equivalent description of its
content.
• ETSI should check that possible implicit conventions used by the authors are explained in the document.
ETSI
13 ETSI EG 204 061 V1.1.1 (2025-10)
Background Information / References
Covered in EN 301 549 [i.7], clause 10.1.3.1.
Covered in EN 301 549 [i.7], clauses 9.1.4.1 and 10.1.4.1, and WCAG Success Criterion 1.4.1 Use of Colour
(WCAG 2.2 [i.3]).
Covered in EN 301 549 [i.7], clauses 9.1.1.1 and 10.1.1.1, and WCAG Success Criterion 1.1.1 Non-text Content
(WCAG) 2.2 [i.3]).
5.2.2 Missing alt text
Accessibility Issue
For tables, pictures, formulae, and other specially formatted content ("Non-text Content"), which may be difficult or
impossible to assess by people with limited eyesight or by the users of screen readers, an alternative textual description
(alt text) should be attached to the Non-text Content.
Explanation
If a document contains pictures, formulae, tables or other content not formatted as running text (Non-text Content), the
users of screen readers or readers with very limited eyesight may not be able to correctly interpret the content of these
sections. For these users, an alternative text-based explanation of the Non-text Content should be made available (alt
text).
Guidelines for authors
• Authors should provide for each picture, table, formulae or other non-text content an alt text description.
Guidelines for ETSI
• ETSI should check that for each picture, table, formulae or other non-text content an alt text description is
available.
Background Information / References
Covered in EN 301 549 [i.7], clauses 9.1.1.1 and 10.1.1.1, and WCAG Success Criterion 1.1.1 Non-text Content
(WCAG 2.2 [i.3]).
5.2.3 Diagrams / Pictures
5.2.3.1 Machine-readable text
Accessibility Issue
A picture or graph should not contain text in binary form, if that text is relevant for the interpretation of the content.
Explanation
Text in binary format is usually not accessible to screen readers. For screen reader users the text should either be
changed to machine-interpretable text (OCR), or the contents should be explained in the alt text.
Guidelines for authors
• Authors should mention in alt text if a picture or graph contains text that is only decorative.
• If a picture or graph contains binary representations of text that is needed for the interpretation of the graph or
the document contents, authors should extract the binary text and apply OCR.
• Authors should replace the binary representation of text with the text extracted by the OCR.
• Authors should explain the contents of text presented in binary format in alt text, if integrating OCR-ed
content is not possible.
ETSI
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