ISO 20271-1

• Abstract:

  This document provides an overview of the ISO 20271 series.

• Status: Not Published
• ICS: 35.240.30 - IT applications in information, documentation and publishing
• ICS: 37.080 - Document imaging applications
• Technical Committee: ISO/TC 171/SC 2 - Document file formats, EDMS systems and authenticity of information
• Drafting Committee: ISO/TC 171/SC 2/WG 10 - File format guidelines
• Current Stage: 6000 - International Standard under publication
• Start Date: 17-Sep-2026
• Completion Date: 10-Oct-2026

ISO 20271-1 is an International Organization for Standardization (ISO) overview of the ISO 20271 series for long-term preservation of textual documents. It explains the series structure, the kinds of document files it addresses, and the roles it is meant to support, so readers can see how the parts fit together before using the technical model.

What does ISO 20271-1 specify?

ISO 20271-1 provides the overview and framework for the ISO 20271 series. It sets out what the series covers, how the parts relate to each other, and how the series can be extended to other document types.

The document is organized into Scope, Summary of the ISO 20271 series, Applicable document types, Exploring applicability and extension to additional document types, Audience, and Bibliography. The introduction also explains that the series is focused on technical characteristics of textual documents and is not a general archival model.

What are the key requirements of ISO 20271-1?

ISO 20271-1 is mainly a guide to the series, but it still makes several practical points that shape how the rest of the series is used.

• Clause 4 presents the ISO 20271 series as a reference model and framework for analysing textual documents in the context of obsolescence. In practice, this tells users to treat preservation as a structured technical review, not just a file-format preference.
• Clause 4.2 says ISO 20271-2 defines a reference model with layers and preservation recommendations for each layer. In practice, users can separate content, metadata, and presentation when judging what must be kept for future access.
• Clause 4.3 says ISO 20271-3 defines a taxonomy for characteristic information and provides a reference markup schema with example instances. In practice, this supports machine-readable description of document properties without forcing one implementation technology.
• Clause 4.4 introduces a preservation assessment methodology as an informative future topic. In practice, this points to quantitative and technical ways to judge preservation risk as the series develops.
• Clause 5 lists the document types in scope, including simple text-based formats, text formats with presentation features, formats with external dependencies, plain-text formats with lightweight markup, packaged formats, and semi-structured textual data formats. In practice, this helps users decide whether their file type fits the series.
• Clause 6 says the model may be extended to other document types by adding layers and properties for their technical characteristics. In practice, teams can adapt the approach for related formats without losing the logic of the model.
• Clause 7 identifies the intended users: archivists, curators, digital preservation specialists, document format developers, researchers, and standards developers. In practice, the document is aimed at people who define formats, assess preservation risk, or plan long-term access.

What terms does ISO 20271-1 define?

• Packaged format - A format that groups text, images, tables, and related objects into one container file for storage, transfer, and preservation.
• Semi-structured data - Data that has some organization but does not follow a rigid, fully predefined structure.
• Textual document - A document where text-based content is the main carrier of meaning, even if it also contains images, audio, or video.
• Reference model - The conceptual structure used in the series to analyse textual documents and their preservation-related layers.
• Layer - A part of the reference model that groups related document characteristics, such as content or metadata.
• Property - A characteristic of a textual document that can be identified, classified, or assessed for preservation.
• Taxonomy - The classification scheme used in the series to organize document characteristics in a consistent way.
• Preservation assessment methodology - The planned method for evaluating preservation objectives, technical risks, and the effect of technological obsolescence.

Who uses ISO 20271-1?

ISO 20271-1 is used by people who need a common technical view of long-term preservation for textual documents. The document is aimed at both specialists who preserve documents and experts who design or standardize document formats.

Typical users include:

• archivists and curators responsible for long-term preservation
• digital preservation specialists managing digital content
• document format developers reducing technical obsolescence
• system architects working on document-management or preservation systems
• researchers and standards developers working on textual-document standards

In practice, these users apply the series when analysing document formats, identifying and classifying properties, defining preservation requirements, and assessing preservation risk over time.

Which standards are used with ISO 20271-1?

ISO 20271-1 is part of the ISO 20271 series, and the document points readers to the other parts of that series as the main companions.

• ISO 20271-2 - provides the reference model for analysing textual document formats and gives preservation recommendations for the model layers.
• ISO 20271-3 - defines the taxonomy for characteristic information and provides reference markup and example instances for representing those properties.

The bibliography also cites related standards and guidance on document formats and long-term preservation, including ISO 19005, ISO 32000, ISO/IEC 26300, ISO/IEC 29500, and ISO/IEC/TS 38505-3.

What does the ISO 20271-1 document contain?

ISO 20271-1 contains a short overview of the series structure, followed by summaries of the other parts and the document types the series addresses. Clause 4 explains how the parts relate, including the reference model in ISO 20271-2 and the taxonomy and markup in ISO 20271-3.

Clause 5 gives examples of the document classes covered, and clause 6 shows how the model may be extended to other document types, including an example for presentation documents with an animation layer and script properties. The introduction explains the preservation problems that motivate the series, such as format obsolescence, compatibility issues, and software or hardware dependencies. The document also includes a bibliography of related standards and guidance.

International
Standard
First edition
Document management —
Reference model for long-
term preservation of textual
documents —
Part 1:
Overview
Gestion des documents — Modèle de référence pour une
conservation à long terme des documents textuels —
Partie 1: Vue d'ensemble
PROOF/ÉPREUVE
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
PROOF/ÉPREUVE
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Summary of the ISO 20271 series . 2
4.1 General .2
4.2 Summary of ISO 20271-2: Fundamental .3
4.3 Summary of the ISO 20271-3: Taxonomy and markup .3
4.4 Preservation assessment methodology .3
5 Applicable document types for ISO 20271 series . 3
6 Exploring applicability and extension to additional document types . 4
7 Audience of the ISO 20271 series . 4
Bibliography . 5
PROOF/ÉPREUVE
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 171, Document management applications,
Subcommittee SC 2, Document file formats, EDMS systems and authenticity of information.
A list of all parts in the ISO 20271 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
PROOF/ÉPREUVE
iv
Introduction
Digital document files vary greatly in type and complexity. They range from simple binary stream files
to text-based files readable by humans, machine-interpretable files, and files that, while human-readable,
require interpretation and re-expression through complex logical structures and relationships.
Textual document file formats can take various forms, including simple binary or text-based structures
and more complex packaged formats that encapsulate multiple components, such as content, metadata
and resources, within a single container structure. Many modern document formats adopt such packaged
formats.
Ensuring long-term preservation and accessibility of these digital documents can be challenging, primarily
due to technical obsolescence, format incompatibilities, or software/hardware dependencies, such as:
— file format compatibility issues:
— file formats are no longer supported;
— new software fails to open correctly files created by the older versions of the same software (no
backward compatibility);
— reliance on proprietary formats rather than on standardized open formats can increase the risk of
format obsolescence and make preservation efforts more challenging e.g. due to inaccessibility of
detailed specifications, unavailability of usable software for handling the formats, or IPR-related
issues;
— limited adoption and support of formats:
— formats are not widely used or supported in the relevant domain;
— formats lack an active user community or support from multiple vendors;
NOTE 1 The use of formats that are widely adopted, based on open specifications, and supported by multiple
vendors can reduce the risk of obsolescence.
— software and hardware dependencies:
— files can only be opened on specific operating systems or software versions;
— compression algorithms, encryption technologies or cryptography-based features used (including
digital signatures, seals and time stamps) are no longer supported;
— lack of preservation policies:
— absence of policies or processes for the long-term preservation of document files;
— insufficient ongoing monitoring of file formats and storage media management.
NOTE 2 Other operational issues such as media ageing, physical corruption, environmental factors, and backup
planning are outside the scope of the ISO 20271 series.
The ISO 20271 series defines technical methods for the selection, verification and assessment of the subjects
of technical review concerning the obsolescence of textual documents. It provides a reference model and
framework for understanding textual documents and the properties that can be present within them.
The reference model addresses technical issues and provides assessment criteria to determine which
digital components (layers) or metadata are desirable or necessary for long-term preservation, as well as
to evaluate the suitability format for this purpose. To support this, the ISO 20271 series is structured as
follows (see Figure 1):
— This document (ISO 20271-1) defines the overall framework, scope and principles for the technical
review of textual document formats in the context of obsolescence. It also provides an explanation of the
structure and scope of the ISO 20271 series to enhance users’ understanding.
PROOF/ÉPREUVE
v
— ISO 20271-2 defines a reference model for textual document formats that can be used to analyse a textual
document file format. It also provides recommendations for preserving each layer of the format, including
content, metadata and presentation, ensuring long-term accessibility and integrity of the document.
— ISO 20271-3specifies properties that can exist in a textual document and provides reference markup for
representing those properties.
The ISO 20271 series is intended for use by organizations and practitioners involved in the creation,
management and preservation of textual documents. This includes developers of document formats,
system architects, archivists, and other stakeholders responsible for ensuring long-term accessibility and
sustainability.
The ISO 20271 series supports activities such as the analysis of textual document formats, the identification
and classification of document properties, the definition of preservation requirements, and the assessment
of long-term preservation risks.
In practice, the ISO 20271 series is intended to be applied as a coherent and iterative process.
ISO 20271-2 provides a reference model for analysing textual document formats by identifying layers and
associated properties.
ISO 20271-3 builds upon this model by defining a taxonomy for classifying the
...

ISO/DISPRF 20271-1:2026(en)
ISO/TC 171/SC 2
Secretariat: ANSI
Date: 2026-03-1308-19
Document management — Reference model for long-term
preservation of textual document - documents —
Part 1:
Overview
Gestion des documents — Modèle de référence pour une conservation à long terme des documents textuels —
Partie 1: Vue d'ensemble
PROOF
ISO/PRF 20271-1:2026(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
-1 2026 – All rights reserved
ii
ISO/DISPRF 20271-1:2026(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Summary of the ISO 20271 series . 2
4.1 General. 2
4.2 Summary of ISO 20271-2: Fundamental . 4
4.3 Summary of the ISO 20271-3: Taxonomy and markup . 4
4.4 Preservation assessment methodology . 4
5 Applicable document types for ISO 20271 series . 4
6 Exploring applicability and extension to additional document types . 5
7 Audience of the ISO 20271 series . 5
Bibliography . 7

iii
ISO/PRF 20271-1:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 171, Document management applications,
Subcommittee SC 2, Document file formats, EDMS systems and authenticity of information.
A list of all parts in the ISO 20271 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

-1 2026 – All rights reserved
iv
ISO/DISPRF 20271-1:2026(en)
Introduction
Digital document files vary greatly in type and complexity. They range from simple binary stream files to text-
based files readable by humans, machine-interpretable files, and files that, while human-readable, require
interpretation and re-expression through complex logical structures and relationships.
Textual document file formats can take various forms, including simple binary or text-based structures and
more complex packaged formats that encapsulate multiple components, such as content, metadata and
resources, within a single container structure. Many modern document formats adopt such packaged formats.
Ensuring long-term preservation and accessibility of these digital documents can be challenging, primarily
due to technical obsolescence, format incompatibilities, or software/hardware dependencies, such as:
— — file format compatibility issues:
— Filefile formats are no longer supported;
— Newnew software fails to open correctly files created by the older versions of the same software (no
backward compatibility);
— Reliancereliance on proprietary formats rather than on standardized open formats can increase the
risk of format obsolescence and make preservation efforts more challenging e.g. due to inaccessibility
of detailed specifications, unavailability of usable software for handling the formats, or IPR-related
issues;
—
— — limited adoption and support of formats:
— Formatsformats are not widely used or supported in the relevant domain;
— Formatsformats lack an active user community or support from multiple vendors;
NOTE — 1 The use of formats that are widely adopted, based on open specifications, and supported by multiple vendors
can reduce the risk of obsolescence.
— — software and hardware dependencies:
— Filesfiles can only be opened on specific operating systems or software versions;
— Compressioncompression algorithms, encryption technologies or cryptography-based features used
(including digital signatures, seals and time stamps) are no longer supported;
—
— — lack of preservation policies:
— Absenceabsence of policies or processes for the long-term preservation of document files;
— Insufficientinsufficient ongoing monitoring of file formats and storage media management.
NOTE 1 2 Other operational issues such as media ageing, physical corruption, environmental factors, and backup
planning are outside the scope of the ISO 20271 series.
v
ISO/PRF 20271-1:2026(en)
The ISO 20271 series defines technical methods for the selection, verification and assessment of the subjects
of technical review concerning the obsolescence of textual documents. It provides a reference model and
framework for understanding textual documents and the properties that maycan be present within them. The
reference model addresses technical issues and provides assessment criteria to determine which digital
components (layers) or metadata are desirable or necessary for long-term preservation, as well as to evaluate
the suitability format for this purpose. To support this, the ISO 20271 series is structured as follows (see
Figure 1Figure 1):):
— — This document (ISO 20271-1) defines the overall framework, scope and principles for the technical
review of textual document formats in the context of obsolescence. It also provides an explanation of the
structure and scope of the ISO 20271 series to enhance users’ understanding.
— — ISO 20271-2 defines a reference model for textual document formats that can be used to analyse a
textual document file format. It also provides recommendations for preserving each layer of the format,
including content, metadata and presentation, ensuring long-term accessibility and integrity of the
document.
— — ISO 20271-3 (under development) is intended to specify3specifies properties that can exist in a textual
document and provides reference markup for representing those properties.
The ISO 20271 series is intended for use by organizations and practitioners involved in the creation,
management and preservation of textual documents. This includes developers of document formats, system
architects, archivists, and other stakeholders responsible for ensuring long-term accessibility and
sustainability.
The ISO 20271 series supports activities such as the analysis of textual document formats, the identification
and classification of document properties, the definition of preservation requirements, and the assessment of
long-term preservation risks.
In practice, the ISO 20271 series is intended to be applied as a coherent and iterative process.
ISO 20271-2 provides a reference model for analysing textual document formats by identifying layers and
associated properties.
ISO 20271-3 builds upon this model by defining a taxonomy for classifying these properties and by providing
non-prescriptive examples of how such properties maycan be represented.
Together, these parts support a structured approach to the analysis, description, and evaluation of textual
document formats in the context of long-term preservation.
Within the reference model, characteristics of textual documents are expressed as properties.
These properties may be associated with one or more layers and form the basis for classification, analysis, and
preservation assessment across the ISO 20271 series.
Some parts of the ISO 20271 series are currently under development or planned, and references to these part
...