ISO/IEC 22121-2:2023

Information technology — Virtual keyboards user interfaces — Part 2: On-screen keyboards with direct touch interface

This document specifies the design and specification of on-screen keyboards (keyboards that are displayed on a screen) with direct touch interface, including those with some audio feedback. This document specifies keyboard layouts designed for on-screen keyboards with direct touch interface and ways for interaction with them. It is not applicable to virtual keyboards that are not displayed on a screen, and on-screen keyboards that do not provide a direct touchscreen interface such as on-screen keyboards relying on an accessory unit like a trackpad or a remote control for interactions with the user. It is not applicable to physical keyboards that use real or adaptable keys, which can be customized to user needs, for example, with LCD display.

Technologies de l'information — Interfaces utilisateurs des claviers virtuels — Partie 2: Claviers sur écran dotés d’interface tactile

General Information

• Status: Published
• Publication Date: 02-Mar-2023
• ICS: 35.180 - IT Terminal and other peripheral equipment
• Technical Committee: ISO/IEC JTC 1/SC 35 - User interfaces
• Drafting Committee: ISO/IEC JTC 1/SC 35/WG 1 - Keyboards, methods and devices related to input and its feedback
• Current Stage: 6060 - International Standard published
• Start Date: 03-Mar-2023
• Due Date: 06-May-2022
• Completion Date: 03-Mar-2023

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 22121-2
First edition
2023-03
Information technology — Virtual
keyboards user interfaces —
Part 2:
On-screen keyboards with direct
touch interface
Technologies de l'information — Interfaces utilisateurs des claviers
virtuels —
Partie 2: Claviers sur écran dotés d’interface tactile
Reference number
ISO/IEC 22121-2:2023(E)
© ISO/IEC 2023

---------------------- Page: 1 ----------------------
ISO/IEC 22121-2:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2023
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
ii
  © ISO/IEC 2023 – All rights reserved

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ISO/IEC 22121-2:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Conformance . 4
4.1 Conformance with this document . 4
4.2 Claims of conformance . 4
5 General requirements for on-screen keyboards with direct touch interface .5
5.1 Character availability . 5
5.2 Single finger/stylus and multiple finger text input . 5
5.3 Adjustment . 6
5.3.1 Long tap duration . 6
5.3.2 Double tap duration . 6
5.3.3 Touchpad pressure . 6
6 Mapping of keyboard layout standards . 6
6.1 General . 6
6.2 Alphabetic characters . 7
6.2.1 Key and row position numbering system . 7
6.2.2 Set of characters to be mapped to on-screen keyboards layouts . 8
6.2.3 Mapping of physical keyboard layout . 9
6.3 Numeric characters . 9
6.4 Space key and other non-graphic keys . 10
6.4.1 Space bar/key . 10
6.4.2 Backspace/backward erase key . 10
6.4.3 Return/enter key. 10
6.4.4 Tabulation key . 11
7 Specific toggle keys and commands .11
7.1 Toggle key layout and operations . 11
7.1.1 General . 11
7.1.2 Location on the on-screen keyboard . 13
7.1.3 Locking/unlocking toggle keys . 13
7.2 Toggle key functionality .13
7.2.1 Level 2 selection toggle key . 13
7.2.2 Group selection toggle key . 14
7.2.3 Layout selection key .15
7.2.4 Speech dictation toggle key . 15
7.2.5 Keyboard deactivation toggle key . 15
7.3 Toggle key status indication .15
8 Associated characters .16
8.1 General . 16
8.2 Access to associated characters . 16
8.2.1 Access to associated characters with a selection box . 16
8.2.2 Access to associated characters with a long tap . 16
8.3 Selection of associated characters . 16
8.3.1 Selection of associated characters with accessible input mode enabled . 16
8.3.2 Selection of associated characters with accessible input mode disabled . 17
8.4 Insertion of associated characters. 18
9 Keyboard mode context dependency .18
9.1 General . 18
9.2 Numeric input fields . 19
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ISO/IEC 22121-2:2023(E)
9.3 Email address input fields . 20
9.4 URL/URI input fields .20
9.5 Input fields with preselected values . 20
10 User customization and creation of new keyboards .20
10.1 Customization of the keyboard .20
10.2 Switching between keyboards . 21
10.3 Loading, saving and sharing the keyboard layout . 21
10.3.1 Modifying a keyboard layout . . 21
10.3.2 Loading a stored keyboard layout . 21
10.3.3 Adding a new keyboard layout. 21
11 Activation/deactivation of on-screen keyboard .21
11.1 Manual activation/deactivation of on-screen keyboard . 21
11.2 Automatic activation/deactivation of on-screen keyboard . 21
11.2.1 Automatic activation . . . 21
11.2.2 Automatic deactivation . 21
11.2.3 Input fields with pre-selected values . 22
11.3 Location of toggle key .22
12 Positioning and sizing .22
12.1 Positioning . 22
12.2 Sizing .22
12.2.1 Relative size of on-screen keyboards . 22
12.2.2 Resizing . 23
12.3 Display space constraints . 23
12.3.1 Key size .23
12.3.2 Number of displayed keys . 24
12.4 Resizing rules . 24
12.5 Field overlapping . 24
12.5.1 General . 24
12.5.2 Context of use . 24
12.5.3 Typing text messages . 24
12.5.4 Typing text on forms .25
12.6 Rotation rules (landscape/portrait) . 25
12.6.1 General . 25
12.6.2 Rotation within applications . 25
12.6.3 Optional resizing .25
13 Shading and styling of on-screen keyboard keys .25
13.1 Contrast ratio . 25
13.2 Highlighting. 25
13.3 Colours and shades . 25
13.4 Key label size . 26
Bibliography .27
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ISO/IEC 22121-2:2023(E)
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see https://patents.iec.ch).
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.
A list of all parts in the ISO/IEC 22121 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 and
www.iec.ch/national-committees.
v
© ISO/IEC 2023 – All rights reserved

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ISO/IEC 22121-2:2023(E)
Introduction
Virtual keyboards can be difficult for users as different types of keyboards and functionalities exist,
and they are spreading exponentially; with the rise of tactile mobile phones and devices, most users in
the world will have to use such interfaces for communication, work or leisure.
The most widespread type of virtual keyboard is found on devices that use both a screen to display the
virtual keyboard (on-screen keyboard) and a built-in, direct touch interface to operate it.
Devices that use an on-screen keyboard with a direct touch interface include at least one touchpad
screen that allows both the display of the keyboard interface and the interaction with the user. These
features are mostly found in handheld devices such as mobile phones, tablets and connected watches,
but can also be seen in other devices such as laptop computers, kiosks, automated teller machine (ATM)
whiteboards, or other touchpad devices used for presentation and demonstration purposes.
The main purpose of this document is to provide a reliable, harmonized and easy-to-use interface for
all on-screen keyboards with a direct touch interface across the various devices that might be using
it, especially mobile and connected devices. It considers a wide range of user needs such as changing
keyboard layouts for multilingual users, customization, responding to accessibility, or adapting the
available keys depending on the context of use, to allow faster typing.
The ISO/IEC 22121 series specifies the requirements and recommendations for all types of virtual
keyboards. This document specifies the requirements and provides further recommendations for on-
screen keyboards with direct touch interface. This document is harmonized with ISO/IEC 24757, which
describes any type of keyboard.
vi
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INTERNATIONAL STANDARD ISO/IEC 22121-2:2023(E)
Information technology — Virtual keyboards user
interfaces —
Part 2:
On-screen keyboards with direct touch interface
1 Scope
This document specifies the design and specification of on-screen keyboards (keyboards that are
displayed on a screen) with direct touch interface, including those with some audio feedback.
This document specifies keyboard layouts designed for on-screen keyboards with direct touch interface
and ways for interaction with them.
It is not applicable to virtual keyboards that are not displayed on a screen, and on-screen keyboards
that do not provide a direct touchscreen interface such as on-screen keyboards relying on an accessory
unit like a trackpad or a remote control for interactions with the user.
It is not applicable to physical keyboards that use real or adaptable keys, which can be customized to
user needs, for example, with LCD display.
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/IEC 9995-1, Information technology — Keyboard layouts for text and office systems — Part 1: General
principles governing keyboard layouts
ISO/IEC 9995-7:2009, Information technology — Keyboard layouts for text and office systems — Part 7:
Symbols used to represent functions
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
on-screen keyboard
virtual keyboard (3.3) displayed on any type of screen
Note 1 to entry: On-screen keyboards are one specific type of virtual keyboards, probably the most common, that
use a screen to display a visual keyboard.
Note 2 to entry: This type of virtual keyboard can be used on personal computer’s screens, on feature phones and
tablets, mobile phones and tablets, TVs, kiosks, whiteboards.
1
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ISO/IEC 22121-2:2023(E)
3.2
physical keyboard
mechanical or electronic input device using an arrangement of buttons or keys
Note 1 to entry: Some physical keyboards are adaptable (for example, using LCD screens instead of keys with
printed symbols and characters).
3.3
virtual keyboard
software alternative to a physical keyboard (3.2)
3.4
associated character
alphabetic character derived from another alphabetic character
Note 1 to entry: Characters can be associated because a diacritic sign is added to it (for example, Ê is associated
to letter E) or because of its close relation to it.
Note 2 to entry: For most languages, using associated characters is essential to write properly.
3.7
qwerty-like on-screen keyboard
virtual keyboard layout used for typing in Latin-based languages, with a layout of alphabetical
characters similar to the physical keyboard layout from which it is derived (qwerty, qwertz, azerty…)
3.8
prediction
software-generated set of characters, i.e. word, phrase or text, based on user typing that can be selected
as next input for faster typing
3.9
group
logical state of a keyboard providing access to a collection of graphic characters (3.13) or elements of
graphic characters
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, may require access to more
than one group.
Note 4 to entry: Subsets of a group are called levels.
[SOURCE: ISO/IEC 9995-1:2009, 4.9]
3.10
level
logical state of a keyboard providing access to a subset of a collection of graphic characters (3.13) or
elements of graphic characters in a group (3.9)
Note 1 to entry: In certain cases, the level selected may also affect function keys.
Note 2 to entry: With on-screen keyboards, it is usual that only one level be shown per panel at a time.
[SOURCE: ISO/IEC 9995-1:2009, 4.11]
2
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ISO/IEC 22121-2:2023(E)
3.11
space key
key associated with character U+0020 SPACE
[SOURCE: ISO/IEC 9995-9:2016, 3.18]
3.12
enter key
key associated with an enter or return function
[SOURCE: ISO/IEC 9995-9:2016, 3.9]
3.13
graphic character
character, other than a control function, that has a visual representation normally handwritten, printed
or displayed
Note 1 to entry: Graphic characters with no visual representation can still be used, as per ISO/IEC 9995-7.
[SOURCE: ISO/IEC 9995-1:2009, 4.1, Note 1 to entry added.]
3.14
graphic symbol
visual representation of a graphic character (3.13), a control function, or a combination of one or more
graphic characters and/or control functions
[SOURCE: ISO/IEC 9995-1:2009, 4.14]
3.15
symbol
any graphic symbol (3.14) which is none of a letter, a digit or a punctuation mark
[SOURCE: ISO/IEC 9995-9:2016, 3.24]
3.16
level 2 select
function that, if activated, will change the keyboard state to produce characters from level 2
Note 1 to entry: Level 2 is particularly associated to case in bicameral scripts (for example, scripts which use
upper and lower case). Other characters are often displayed at the same time in level 2 when space allows it in the
same panel.
Note 2 to entry: By default, level 2 select is activated only for the next keystroke.
Note 3 to entry: Level 2 select may be locked similarly to the capital state lock function.
[SOURCE: ISO/IEC 9995-1:2009, 4.15, modified — Notes 2 and 3 to entry added.]
3.17
group select
function that, if activated, will change the keyboard state to produce characters from a different group
[SOURCE: ISO/IEC 9995-1:2009, 4.13]
3.18
capitals lock state
state that, if activated, will result in the generation of the capital form of all graphic characters (3.13) on
the keyboard for which such a form exists
[SOURCE: ISO/IEC 9995-1:2009, 4.7]
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ISO/IEC 22121-2:2023(E)
3.19
toggle key
on-screen keyboard key that provides a choice of two states
Note 1 to entry: Toggle keys can be used to access a collection of graphic characters.
Note 2 to entry: Toggle keys can provide access to menus for item selection.
Note 3 to entry: Different symbols can be used to display the toggle key status.
3.20
toggle key status
state of the toggle key (3.19) activated by the user
3.21
tap
single consecutive touch and release actions on a touchscreen device, typically it finishes shorter than
500 ms
Note 1 to entry: The touch action can be performed by any part of the human body (usually, the fingers), a pen,
stylus, or any other stylus shaped object.
3.22
long tap
single consecutive touch, hold and release actions on a touchscreen device, typically
...

FINAL
INTERNATIONAL ISO/IEC
DRAFT
STANDARD FDIS
22121-2
ISO/IEC JTC 1/SC 35
Information technology — Virtual
Secretariat: AFNOR
keyboards user interfaces —
Voting begins on:
2022-12-14
Part 2:
Voting terminates on:
On-screen keyboards with direct
2023-02-08
touch interface
Technologies de l'information — Interfaces utilisateurs des claviers
virtuels —
Partie 2: Claviers sur écran dotés d’interface tactile
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/IEC FDIS 22121-2:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO/IEC 2022

---------------------- Page: 1 ----------------------
ISO/IEC FDIS 22121-2:2022(E)
FINAL
INTERNATIONAL ISO/IEC
DRAFT
STANDARD FDIS
22121-2
ISO/IEC JTC 1/SC 35
Information technology — Virtual
Secretariat: AFNOR
keyboards user interfaces —
Voting begins on:
Part 2:
Voting terminates on:
On-screen keyboards with direct
touch interface
Technologies de l'information — Interfaces utilisateurs des claviers
virtuels —
Partie 2: Claviers sur écran dotés d’interface tactile
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2022
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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/IEC FDIS 22121­2:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO/IEC 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO/IEC 2022

---------------------- Page: 2 ----------------------
ISO/IEC FDIS 22121-2:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Conformance . 4
4.1 Conformance with this document . 4
4.2 Claims of conformance . 4
5 General requirements for on-screen keyboards with direct touch interface .5
5.1 Character availability . 5
5.2 Single finger/stylus and multiple finger text input . 5
5.3 Adjustment . 6
5.3.1 Long tap duration . 6
5.3.2 Double tap duration . 6
5.3.3 Touchpad pressure . 6
6 Mapping of keyboard layout standards . 6
6.1 General . 6
6.2 Alphabetic characters . 7
6.2.1 Key and row position numbering system . 7
6.2.2 Set of characters to be mapped to on-screen keyboards layouts . 8
6.2.3 Mapping of physical keyboard layout . 9
6.3 Numeric characters . 9
6.4 Space key and other non-graphic keys . 10
6.4.1 Space bar/key . 10
6.4.2 Backspace/backward erase key . 10
6.4.3 Return/enter key. 10
6.4.4 Tabulation key . 11
7 Specific toggle keys and commands .11
7.1 Toggle key layout and operations . 11
7.1.1 General . 11
7.1.2 Location on the on-screen keyboard . 13
7.1.3 Locking/unlocking toggle keys . 13
7.2 Toggle key functionality .13
7.2.1 Level 2 selection toggle key . 13
7.2.2 Group selection toggle key . 14
7.2.3 Layout selection key .15
7.2.4 Speech dictation toggle key . 15
7.2.5 Keyboard deactivation toggle key . 15
7.3 Toggle key status indication .15
8 Associated characters .16
8.1 General . 16
8.2 Access to associated characters . 16
8.2.1 Access to associated characters with a selection box . 16
8.2.2 Access to associated characters with a long tap . 16
8.3 Selection of associated characters . 16
8.3.1 Selection of associated characters with accessible input mode enabled . 16
8.3.2 Selection of associated characters with accessible input mode disabled . 17
8.4 Insertion of associated characters. 18
9 Keyboard mode context dependency .18
9.1 General . 18
9.2 Numeric input fields . 19
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ISO/IEC FDIS 22121-2:2022(E)
9.3 Email address input fields . 20
9.4 URL/URI input fields .20
9.5 Input fields with preselected values . 20
10 User customization and creation of new keyboards .20
10.1 Customization of the keyboard .20
10.2 Switching between keyboards . 21
10.3 Loading, saving and sharing the keyboard layout . 21
10.3.1 Modifying a keyboard layout . . 21
10.3.2 Loading a stored keyboard layout . 21
10.3.3 Adding a new keyboard layout. 21
11 Activation/deactivation of on-screen keyboard .21
11.1 Manual activation/deactivation of on-screen keyboard . 21
11.2 Automatic activation/deactivation of on-screen keyboard . 21
11.2.1 Automatic activation . . . 21
11.2.2 Automatic deactivation . 21
11.2.3 Input fields with pre-selected values . 22
11.3 Location of toggle key .22
12 Positioning and sizing .22
12.1 Positioning . 22
12.2 Sizing .22
12.2.1 Relative size of on-screen keyboards . 22
12.2.2 Resizing . 23
12.3 Display space constraints . 23
12.3.1 Key size .23
12.3.2 Number of displayed keys . 24
12.4 Resizing rules . 24
12.5 Field overlapping . 24
12.5.1 General . 24
12.5.2 Context of use . 24
12.5.3 Typing text messages . 24
12.5.4 Typing text on forms .25
12.6 Rotation rules (landscape/portrait) . 25
12.6.1 General . 25
12.6.2 Rotation within applications . 25
12.6.3 Optional resizing .25
13 Shading and styling of on-screen keyboard keys .25
13.1 Contrast ratio . 25
13.2 Highlighting. 25
13.3 Colours and shades . 25
13.4 Key label size . 26
Bibliography .27
iv
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ISO/IEC FDIS 22121-2:2022(E)
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 non­governmental, 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see http://patents.iec.ch).
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 Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 35, User interfaces.
A list of all parts in the ISO/IEC 22121 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.
v
© ISO/IEC 2022 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/IEC FDIS 22121-2:2022(E)
Introduction
Virtual keyboards can be difficult for users as different types of keyboards and functionalities exist,
and they are spreading exponentially; with the rise of tactile mobile phones and devices, most users in
the world will have to use such interfaces for communication, work or leisure.
The most widespread type of virtual keyboard is found on devices that use both a screen to display the
virtual keyboard (on-screen keyboard) and a built-in, direct touch interface to operate it.
Devices that use an on-screen keyboard with a direct touch interface include at least one touchpad
screen that allows both the display of the keyboard interface and the interaction with the user. These
features are mostly found in handheld devices such as mobile phones, tablets and connected watches,
but can also be seen in other devices such as laptop computers, kiosks, automated teller machine (ATM)
whiteboards, or other touchpad devices used for presentation and demonstration purposes.
The main purpose of this document is to provide a reliable, harmonized and easy-to-use interface for
all on-screen keyboards with a direct touch interface across the various devices that might be using
it, especially mobile and connected devices. It considers a wide range of user needs such as changing
keyboard layouts for multilingual users, customization, responding to accessibility, or adapting the
available keys depending on the context of use, to allow faster typing.
The ISO/IEC 22121 series specifies the requirements and recommendations for all types of virtual
keyboards. This document specifies the requirements and provides further recommendations for on-
screen keyboards with direct touch interface. This document is harmonized with ISO/IEC 24757, which
describes any type of keyboard.
vi
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---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/IEC FDIS 22121-2:2022(E)
Information technology — Virtual keyboards user
interfaces —
Part 2:
On-screen keyboards with direct touch interface
1 Scope
This document specifies the design and specification of on-screen keyboards (keyboards that are
displayed on a screen) with direct touch interface, including those with some audio feedback.
This document specifies keyboard layouts designed for on-screen keyboards with direct touch interface
and ways for interaction with them.
It is not applicable to virtual keyboards that are not displayed on a screen, and on-screen keyboards
that do not provide a direct touchscreen interface such as on-screen keyboards relying on an accessory
unit like a trackpad or a remote control for interactions with the user.
It is not applicable to physical keyboards that use real or adaptable keys, which can be customized to
user needs, for example, with LCD display.
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/IEC 9995­1:2009, Information technology — Keyboard layouts for text and office systems — Part 1:
General principles governing keyboard layouts
ISO/IEC 9995­7, Information technology — Keyboard layouts for text and office systems — Part 7: Symbols
used to represent functions
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
on-screen keyboard
virtual keyboard (3.3) displayed on any type of screen
Note 1 to entry: On-screen keyboards are one specific type of virtual keyboards, probably the most common, that
use a screen to display a visual keyboard.
Note 2 to entry: This type of virtual keyboard can be used on personal computer’s screens, on feature phones and
tablets, mobile phones and tablets, TVs, kiosks, whiteboards.
1
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ISO/IEC FDIS 22121-2:2022(E)
3.2
physical keyboard
mechanical or electronic input device using an arrangement of buttons or keys
Note 1 to entry: Some physical keyboards are adaptable (for example, using LCD screens instead of keys with
printed symbols and characters).
3.3
virtual keyboard
software alternative to a physical keyboard (3.2)
3.4
associated character
alphabetic character derived from another alphabetic character
Note 1 to entry: Characters can be associated because a diacritic sign is added to it (for example, Ê is associated
to letter E) or because of its close relation to it.
Note 2 to entry: For most languages, using associated characters is essential to write properly.
3.7
qwerty-like on-screen keyboard
virtual keyboard layout used for typing in Latin-based languages, with a layout of alphabetical
characters similar to the physical keyboard layout from which it is derived (qwerty, qwertz, azerty…)
3.8
prediction
software-generated set of characters, i.e. word, phrase or text, based on user typing that can be selected
as next input for faster typing
3.9
group
logical state of a keyboard providing access to a collection of graphic characters (3.13) or elements of
graphic characters
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, may require access to more
than one group.
Note 4 to entry: Subsets of a group are called levels.
[SOURCE: ISO/IEC 9995­1:2009, 4.9]
3.10
level
logical state of a keyboard providing access to a subset of a collection of graphic characters (3.13) or
elements of graphic characters in a group (3.9)
Note 1 to entry: In certain cases, the level selected may also affect function keys.
Note 2 to entry: With on-screen keyboards, it is usual that only one level be shown per panel at a time.
[SOURCE: ISO/IEC 9995­1:2009, 4.11]
2
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ISO/IEC FDIS 22121-2:2022(E)
3.11
space key
key associated with character U+0020 SPACE
[SOURCE: ISO/IEC 9995­9:2016, 3.18]
3.12
enter key
key associated with an enter or return function
[SOURCE: ISO/IEC 9995­9:2016, 3.9]
3.13
graphic character
character, other than a control function, that has a visual representation normally handwritten, printed
or displayed
Note 1 to entry: Graphic characters with no visual representation can still be used, as per ISO/IEC 9995-7.
[SOURCE: ISO/IEC 9995-1:2009, 4.1, Note 1 to entry added.]
3.14
graphic symbol
visual representation of a graphic character (3.13), a control function, or a combination of one or more
graphic characters and/or control functions
[SOURCE: ISO/IEC 9995­1:2009, 4.14]
3.15
symbol
any graphic symbol (3.14) which is none of a letter, a digit or a punctuation mark
[SOURCE: ISO/IEC 9995­9:2016, 3.24]
3.16
level 2 select
function that, if activated, will change the keyboard state to produce characters from level 2
Note 1 to entry: Level 2 is particularly associated to case in bicameral scripts (for example, scripts which use
upper and lower case). Other characters are often displayed at the same time in level 2 when space allows it in the
same panel.
Note 2 to entry: By default, level 2 select is activated only for the ne
...

ISO/IEC DISFDIS 22121-2:2022(E)
2022-11-30
ISO/IEC JTC 1/SC 35/WG 1
Secretariat: AFNOR
Information technology — Virtual keyboards user interfaces — Part 2: On-screen keyboards
with direct touch interface
Technologies de l'information — Interface utilisateur des claviers virtuels — Partie 2 : Claviers
sur écran doté d’interface tactile
FDIS stage

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© ISO/IEC 2020 2022
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’sISO's member body in the country of the requester.
ISO copyright officeCopyright Office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Fax: [phone]
Email: [e-mail]
Email: [e-mail]
Website: www.iso.orgwww.iso.org
Published in Switzerland.
© ISO/IEC 2020 – All rights reserved     2

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ISO/IEC DISFDIS 22121-2:2020(E)
Contents

Foreword . vi
Introduction. vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Conformance . 4
4.1 Conformance with this document . 4
4.2 Claims of conformance . 5
5 General requirements for on-screen keyboards with direct touch interface . 5
5.1 Character availability. 5
Figure 1 — Example of an AAC on-screen keyboard used for symbol communication . 5
5.2 Single finger/stylus and multiple finger text input . 6
5.3 Adjustment . 6
5.3.1 Long tap duration . 6
5.3.2 Double tap duration . 6
5.3.3 Touchpad pressure . 6
6 Mapping of keyboard layout standards. 7
6.1 General . 7
6.2 Alphabetic characters . 7
6.2.1 Key and row position numbering system . 7
6.2.2 Set of characters to be mapped to on-screen keyboards layouts . 8
Figure 4 — Example of the required set of characters for the QWERTY keyboard layout . 9
Figure 5 — Example of a mapping of an AZERTY keyboard layout on a French on-screen
keyboard . 9
6.2.3 Mapping of physical keyboard layout . 9
6.3 Numeric characters . 10
Figure 6 — Example of an on-screen keyboard using an additional row to provide access to
numeric characters . 10
6.4 Space key and other non-graphic keys . 10
6.4.1 Space bar/key . 10
6.4.2 Backspace/backward erase key . 11
6.4.3 Return/enter key. 11
6.4.4 Tabulation key . 11
7 Specific toggle keys and commands . 12
7.1 Toggle key layout and operations . 12
7.1.1 General . 12
Figure 7 — Example of a level 2 select toggle key with an on-screen keyboard . 12
Figure 8 — Example of a language selection toggle key menu with an on-screen keyboard . 13
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ISO/IEC DISFDIS 22121-2:2020(E)
Figure 9 — Example of a language selection toggle key with an on-screen keyboard . 13
7.1.2 Location on the on-screen keyboard . 14
7.1.3 Locking/unlocking toggle keys . 14
7.2 Toggle key functionality . 14
7.2.1 Level 2 selection toggle key . 14
7.2.2 Group selection toggle key . 15
7.2.3 Layout selection key . 15
7.2.4 Speech dictation toggle key . 16
7.2.5 Keyboard deactivation toggle key . 16
7.3 Toggle key status indication . 16
8 Associated characters . 16
8.1 General . 16
8.2 Access to associated characters . 17
8.2.1 Access to associated characters with a selection box. 17
8.2.2 Access to associated characters with a long tap . 17
8.3 Selection of associated characters . 17
8.3.1 Selection of associated characters with accessible input mode enabled . 17
8.3.2 Selection of associated characters with accessible input mode disabled . 19
Figure 11 — Example of an associated character selection box . 19
8.4 Insertion of associated characters . 19
9 Keyboard mode context dependency . 20
9.1 General . 20
9.2 Numeric input fields . 20
Figure 12 — 1-2-3 numeric keyboard layout as standardized in ISO/IEC 9995-4 . 20
Figure 12 — 1-2-3 numeric keyboard layout as standardized in ISO/IEC 9995-4 . 21
Figure 13 — Numeric input with a numeric on-screen keyboard layout on a handheld
device . 21
9.3 Email address input fields . 21
9.4 URL/URI input fields . 21
9.5 Input fields with preselected values. 21
10 User customization and creation of new keyboards . 22
10.1 Customization of the keyboard . 22
10.2 Switching between keyboards . 22
10.3 Loading, saving and sharing the keyboard layout . 22
10.3.1 Modifying a keyboard layout. 22
10.3.2 Loading a stored keyboard layout . 22
10.3.3 Adding a new keyboard layout . 22
11 Activation/deactivation of on-screen keyboard . 22
11.1 Manual activation/deactivation of on-screen keyboard . 22
11.2 Automatic activation/deactivation of on-screen keyboard . 23
11.2.1 Automatic activation . 23
11.2.2 Automatic deactivation . 23
11.2.3 Input fields with pre-selected values . 23
11.3 Location of toggle key . 23
12 Positioning and sizing . 23
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ISO/IEC DISFDIS 22121-2:2020(E)
12.1 Positioning . 23
12.2 Sizing . 24
12.2.1 Relative size of on-screen keyboards . 24
Figure 14 — On-screen keyboard general organisation . 24
12.2.2 Resizing . 24
12.3 Display space constraints . 25
12.3.1 Key size. 25
12.3.2 Number of displayed keys . 25
12.4 Resizing rules . 25
12.5 Field overlapping. 26
12.5.1 General . 26
12.5.2 Context of use . 26
12.5.3 Typing text messages . 26
12.5.4 Typing text on forms . 26
12.6 Rotation rules (landscape/portrait) . 26
12.6.1 General . 26
12.6.2 Rotation within applications . 26
12.6.3 Optional resizing . 26
13 Shading and styling of on-screen keyboard keys . 27
13.1 Contrast ratio . 27
13.2 Highlighting . 27
13.3 Colours and shades . 27
13.4 Key label size . 27
Bibliography . 28


Foreword . 8
Introduction. 9
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Conformance . 5
4.1 Conformance with this document . 5
4.2 Claims of conformance . 5
5 General requirements for on-screen keyboards with direct touch interface . 5
5.1 Character availability. 5
5.2 Single finger/stylus and multiple finger text input . 7
5.3 Adjustment . 7
5.3.1 Long tap duration . 7
5.3.2 Double tap duration . 7
5.3.3 Touchpad pressure . 8
6 Mapping of keyboard layout standards. 8
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ISO/IEC DISFDIS 22121-2:2020(E)
6.1 General . 8
6.2 Alphabetic characters . 8
6.2.1 Key and row position numbering system . 8
6.2.2 Set of characters to be mapped to on-screen keyboards layouts . 11
6.2.3 Mapping of physical keyboard layout . 12
6.3 Numeric characters . 13
6.4 Space key and other non-graphic keys . 14
6.4.1 Space bar/key . 14
6.4.2 Backspace/backward erase key . 14
6.4.3 Return/enter key. 14
6.4.4 Tabulation key . 15
7 Specific toggle keys and commands . 15
7.1 Toggle key layout and operations . 15
7.1.1 General . 15
7.1.2 Location on the on-screen keyboard . 18
7.1.3 Locking/unlocking toggle keys . 18
7.2 Toggle key functionality . 18
7.2.1 Level 2 selection toggle key . 18
7.2.2 Group selection toggle key . 19
7.2.3 Layout selection key . 20
7.2.4 Speech dictation toggle key . 20
7.2.5 Keyboard deactivation toggle key . 20
7.3 Toggle key status indication . 21
8 Associated characters . 21
8.1 General . 21
8.2 Access to associated characters . 21
8.2.1 Access to associated characters with a selection box . 21
8.2.2 Access to associated characters with a long tap . 21
8.3 Selection of associated characters . 22
8.3.1 Selection of associated characters with accessible input mode enabled . 22
8.3.2 Selection of associated characters with accessible input mode disabled . 24
8.4 Insertion of associated characters . 25
9 Keyboard mode context dependency . 25
9.1 General . 25
9.2 Numeric input fields . 25
9.3 Email address input fields . 28
9.4 URL/URI input fields . 28
9.5 Input fields with preselected values. 28
10 User customization and creation of new keyboards . 28
10.1 Customization of the keyboard . 28
10.2 Switching between keyboards . 29
10.3 Loading, saving and sharing the keyboard layout . 29
10.3.1 Modifying a keyboard layout. 29
10.3.2 Loading a stored keyboard layout . 29
10.3.3 Adding a new keyboard layout . 29
11 Activation/deactivation of on-screen keyboard . 29
11.1 Manual activation/deactivation of on-screen keyboard . 29
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ISO/IEC DISFDIS 22121-2:2020(E)
11.2 Automatic activation/deactivation of on-screen keyboard . 29
11.2.1 Automatic activation . 29
11.2.2 Automatic deactivation . 29
11.2.3 Input fields with pre-selected values . 30
11.3 Location of toggle key . 30
12 Positioning and sizing . 30
12.1 Positioning . 30
12.2 Sizing . 30
12.2.1 Relative size of on-screen keyboards . 30
12.2.2 Resizing . 32
12.3 Display space constraints . 32
12.3.1 Key size. 32
12.3.2 Number of displayed keys . 33
12.4 Resizing rules . 33
1
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