ISO/IEC 9995-1

INTERNATIONAL STANDARD FDIS DRAFT
ISO/IEC FDIS 9995-1:2025(en)
ISO/IEC JTC 1/SC 35
Secretariat: AFNOR
Fourth edition
Date: 2025-08-16
Information technology — Keyboard layouts for text and office
systems —
Part 1:
General principles governing keyboard layouts
Technologies de l'information — Disposition des claviers conçus pour la bureautique —
Partie 1: Principes généraux pour la disposition des claviers
FDIS stage
ISO/IEC FDIS 9995-1:2025(en)
© ISO/IEC 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
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© ISO/IEC 2025 – All rights reserved
ii
ISO/IEC FDIS 9995-1:2025(en)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Divisions of the keyboard . 4
4.1 General . 4
4.2 Logical division of keyboard into groups and levels . 4
4.3 Physical division of keyboard into sections and zones . 6
4.4 Placement of sections . 9
5 Methods of indicating allocations to keys . 9
6 Key position numbering system . 10
6.1 Principle of the grids . 10
6.2 Designation of key positions . 12
6.3 Reference positions for the rows and columns . 13
6.4 Key location numbering requirements . 13
7 General principles of key labelling and symbol positioning . 13
7.1 General . 13
7.2 Positions of the symbols on the keys . 13
7.3 Capital/small letter pairs . 19
7.4 Minimum required size of keytop symbols . 19
8 Key arrangement and distances . 19
8.1 Key arrangement . 19
8.2 Other requirements . 19
Annex A (informative) Examples of national standards . 20
Bibliography . 21

© ISO/IEC 2025 – All rights reserved
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ISO/IEC FDIS 9995-1:2025(en)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members
of ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work.
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
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 or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the use of
(a) patent(s). ISO and IEC take 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 and IEC 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 and https://patents.iec.ch. ISO and IEC 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.
In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 35, User interfaces.
This fourth edition cancels and replaces the third edition (ISO/IEC 9995-1:2009), which has been technically
revised.
The main changes are as follows:
— — A Level 4 is allowed, albeit not recommended;
— Clause 8— Clause 8 is enhanced to be usable for keyboard layouts according to the state of the art,
showing characters of up to four levels and of several groups.
A list of all parts in the ISO/IEC 9995 series can be found on the ISO and IEC websites.
For some national standards based on the ISO/IEC 9995 series, see Annex A.
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 and www.iec.ch/national-
committees.
© ISO/IEC 2025 – All rights reserved
iv
ISO/IEC FDIS 9995-1:2025(en)
Introduction
The lSO/IEC 9995 series defines a framework for the layout of all alphanumeric and numeric keyboards across
the widest spectrum of today's and upcoming applications using keyboards. The functions to be performed by
keyboards are grouped into three categories that correspond to the main physical sections of the keyboard.
Application of the lSO/IEC 9995 series in the design of keyboards provides the user with a unified, predictable
user-machine interface by dividing the keyboard into functional areas and sections and allocating functions to
keys. One of the major tasks of a universal-usage keyboard is to accommodate the larger sets of characters
required by the various applications for which keyboards are used today. This is achieved by permitting the
allocation of more than one graphic character or control function to each of the keys of a keyboard,
predominantly in the alphanumeric section.
The ISO/IEC 9995 series specifies the requirements for keyboard layouts and allocation of keycap imprints
(including letters, numerals, symbols, and other markings) on alphanumeric and numeric input devices for all
types of information and communication technology apparatus and systems including:
— — personal computers, workstations, computer terminals, visual display terminals (VDTs);
— — electronic typewriters and other machines with alphanumeric and numeric keyboards;
— — mobile computer systems including ultra-mobile personal computers (UMPCs), personal digital
assistants (PDAs) and multimedia devices with hardware keyboards (e.g. linear keyboards, foldable
keyboards) or virtual keyboards (e.g. touchscreens, projection keyboards);
— — electronic document scanners and multifunction devices incorporating alphanumeric or numeric
keyboards;
— — calculators, telephones and automated teller machines having alphanumeric or numeric
keypads/keyboards.
The primary layout within the alphanumeric zone is established in most countries by a national standard or
by national usage. Allocation guidelines are provided in lSO/IEC 9995-2. An exemplary layout (the “Latin
International” keyboard layout) is specified in lSO/lEC 9995-3.
The lSO/IEC 9995 series specifies the allocation of functions (graphic characters and/or control functions, or
both) to keys. The graphic characters and the control functions have been given common names intended to
be familiar to the users of a keyboard. In general, keyboards are not expected to generate coded control
functions, but the operation of a control function key can cause a number of coded control functions to appear
in data interchange to achieve the desired effect.
The effects of those keys that affect keyboard states are specified in other parts of the lSO/IEC 9995 series.
For some national standards based on the ISO/IEC 9995 series, see Annex A.
© ISO/IEC 2025 – All rights reserved
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ISO/IEC FDIS 9995-1:2025(en)
Information technology — Keyboard layouts for text and office
systems —
Part 1:
General principles governing keyboard layouts
1 Scope
This document identifies the sections of the keyboard and specifies the general shape and relative placement
of the sections. Spacing of keys and physical characteristics are covered, as are the principles governing the
placement of characters and symbols on keys.
It specifies a key numbering system which applies to all types of numeric, alphanumeric and composite
keyboards of information technology equipment (ITE).
It specifies the principles governing the placement of characters and symbols on keys used on all types of
numeric, alphanumeric and composite keyboards of ITE. Although the keyboard defined by the lSO/IEC 9995
series can be used for different languages, the specifications are written as applying to Latin languages with a
character path from left to right and a line progression from top to bottom.
It defines characteristics related to interface 1 in Figure 1Figure 1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 9241--410, Ergonomics of human-system interaction — Part 410: Design criteria for physical input devices
ISO/IEC 9995 (all parts), Information technology — Keyboard layouts for text and office systems
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 3.1
graphic character
character, other than a control function, that has a visual representation, normally handwritten, printed or
displayed
3.2 3.2
primary group layout
allocation of the graphic characters of group 1 to the keys of a particular keyboard, defined by a national
standard or established by common usage in a particular country or group of countries
© ISO/IEC 2025 – All rights reserved
ISO/IEC FDIS 9995-1:2025(en)
3.3 3.3
secondary group layout
allocation of the graphic characters of group 2 to the keys of a particular keyboard
3.4 3.4
key effect
effect that results when a key is actuated, depending on the active level, and possibly by the concurrent
operation of a qualifier key or keys
3.5 3.5
lock state
state set by actuating a lock key, singly or in combination with a qualifier key
3.6 3.6
level lock state
state that, if activated, will result in the generation of the characters assigned to a specific level
3.7 3.7
capitals lock state
state that, if activated, will result in the generation of the capital form of all graphic characters on the keyboard
for which such a form exists
3.8 3.8
control function
action that affects the recording, processing, transmission, or interpretation of data
3.9 3.9
group
logical state of a keyboard providing access to a collection of graphic characters or elements of graphic
characters whose subsets are called levels
Note 1 to entry: A group gives access to one collection of characters. Typically, when more than one language is used,
multiple groups are required.
Note 2 to entry: Usually these graphic characters or elements of graphic characters logically belong together and can be
arranged on several levels within a group.
Note 3 to entry: The input of certain graphic characters, such as accented letters, can require access to more than one
group.
Note 4 to entry: On on-screen keyboards, it is usual that a group be shown one level at a time. There is usually a button
to choose the group (or language) and another button, or more, to choose the level.
3.10 3.10
section
block of keys, mostly with some functional relationship
3.11 3.11
level
logical state of a keyboard providing access to a collection of graphic characters or elements of graphic
characters
Note 1 to entry: Usually these graphic characters or elements of graphic characters logically belong together, such as the
capital forms of letters.
Note 2 to entry: In certain cases the level selected can also affect function keys.
© ISO/IEC 2025 – All rights reserved
ISO/IEC FDIS 9995-1:2025(en)
Note 3 to entry: On physical keyboards, levels of a same group are normally labelled in a consistent way (see
Clause 8Clause 8)) on a key except when stated otherwise in certain situations; on on-screen keyboards, it is usual that
only one level be shown per panel at a time.
3.12 3.12
active position
character position which is to image the graphic symbol representing the next graphic character or relative to
which the next control function is to be executed
Note 1 to entry: In general, the active position is indicated in a display by a cursor.
3.13 3.13
group select
function that, if activated, will change the keyboard state to produce characters from a different group
3.14 3.14
group single-select
function that, if activated, will change the keyboard state to produce characters from a different group only
for the input of the next character, changing to the previous state after that
3.15 3.15
graphic symbol
visual representation of a graphic character, a control function, or a combination of one or more graphic
characters and/or control functions
3.16 3.16
level select
function that, if activated, will change the keyboard state to produce characters from a different level
3.17 3.17
level single-select
function that, if activated, will change the keyboard state to produce characters from a different level only for
the input of the next character, changing to the previous state after that
3.18 3.18
associated system
system to which the keyboard is attached, probably consisting of a processor and software to handle the
keyboard and to run application programs
3.19 3.19
editing key
key whose primary purpose is the input of an editing function
3.20 3.20
function key
key whose primary purpose is the input of a control function
3.21 3.21
graphic key
key whose primary purpose is the input of a graphic character or of an element of a graphic character
Note 1 to entry: Certain of these keys can also have a secondary purpose for input of a control function.
3.22 3.22
zone
part of a keyboard section defined in the ISO/IEC 9995 series
© ISO/IEC 2025 – All rights reserved
ISO/IEC FDIS 9995-1:2025(en)
4 Divisions of the keyboard
4.1 General
For the purpose of this document, the keyboard is considered as an intermediate element between a user and
an information processing system. The keyboard is specifically intended as a means for input of information
by a human being, see Figure 1Figure 1.
Simply stated, the keyboard functions as follows:
— — the user actuates one or more keys (event at interface 1);
— — corresponding signals are sent to the information processing system (event at interface 2).
For the purpose of this document the keyboard is considered to be divided logically into groups and levels and
physically into sections and zones, in which the individual keys are arranged. The individual keys should
conform to the physical requirements laid out in ISO 9241-410, Ergonomics of human-system interaction —
Part 410: Design criteria for physical input devices-410.

Key
1 user
2 keyboard
3 associated system
4 interface 1
5 interface 2
NOTE Not drawn to scale - all lines are only indicative.
Figure 1 — Keyboard interfaces
4.2 Logical division of keyboard into groups and levels
4.2.1 General
The graphic characters or control functions which may be accessed by one key are logically arranged in groups
and levels. The traditional shift function has been extended to permit access to these different groups and
© ISO/IEC 2025 – All rights reserved
ISO/IEC FDIS 9995-1:2025(en)
levels. The selection among the available groups and levels is controlled by the user by means of one or more
select mechanisms (see Table 1Table 1).).
Groups are likely to contain complete or distinctive sets of functions. A keyboard could have any number of
groups, practicality of use being a limiting factor.
Within each group, functions (graphic characters and/or control functions, or both) are arranged on up to four
levels.
Characters in more than one group need not be always labelled on a key of a physical keyboard.
4.2.2 Group and level select mechanisms
Implementation-defined methods may be defined for group selection, as long as the methods prescribed in
different parts of the ISO/IEC 9995 series are provided.
Two kinds of select mechanisms are recognized here:
— — group select: enables selection among groups;
— — level select: enables selection among levels.
The two functions can apply simultaneously. In a hierarchical sense the group is higher than the level; within
a group several levels may be defined.
Table 1 — Logical division into groups and levels
Active Group and
Group Select Level Select
Level
None None Group 1, Level 1
(default = Group 1) Level 2 select Group 1, Level 2
Level 3 select Group 1, Level 3
a
Level 4 select Group 1, Level 4
Yes None Group n, Level 1
(To group n) Level 2 select Group n, Level 2
Level 3 select Group n, Level 3
a
Level 4 select Group n, Level 4
a This function may be selected by simultaneously activating Level 2 select and Level 3 select.
Groups beyond group 1 are accessed via a group select or a group single-select function. Level 1, formerly
called the unshifted level, is accessible without a level select function. The levelLevel 2 select function provides
access to levelLevel 2, formerly called the shifted level. Level 3 and 4 are accessed through additional level
select functions provided for that purpose.
The concept of selecting groups and levels can be applied to sections of the keyboard other than the
alphanumeric section.
4.2.3 Usage of Level 4
If the keyboard layout does not contain a specific Level 4 select function, the Level 4 should be accessible by
simultaneously activating the Level 2 select function and the Level 3 Select function.
© ISO/IEC 2025 – All rights reserved
ISO/IEC FDIS 9995-1:2025(en)
NOTE 1 Using Level 4 in this way has the disadvantage that it needs the simultaneous use of using three fingers at the
same time to enter a character, unless there a locking mechanism is provided. Such a mechanism can be provided e.g. by
using a key combination like Control + Level 3 select (Alt Gr) as a “Level 3+4 single-lo
...