ISO/IEC 23360-1-2:2021
(Main)Linux Standard Base (LSB) — Part 1-2: Core specification generic part
Linux Standard Base (LSB) — Part 1-2: Core specification generic part
This document defines a system interface for compiled applications and a minimal environment for support of installation scripts. Its purpose is to enable a uniform industry standard environment for high-volume applications conforming to the LSB. These specifications are composed of two basic parts: a common part describing those parts of the interface that remain constant across all implementations of the LSB, and an architecture-specific part describing the parts of the interface that vary by processor architecture. Together, the common part and the relevant architecture-specific part for a single hardware architecture provide a complete interface specification for compiled application programs on systems that share a common hardware architecture. The LSB contains both a set of Application Program Interfaces (APIs) and Application Binary Interfaces (ABIs). APIs may appear in the source code of portable applications, while the compiled binary of that application may use the larger set of ABIs. A conforming implementation provides all of the ABIs listed here. The compilation system may replace (e.g. by macro definition) certain APIs with calls to one or more of the underlying binary interfaces, and may insert calls to binary interfaces as needed. The LSB is primarily a binary interface definition. Not all of the source level APIs available to applications may be contained in this specification. This is the common part of the Core module of the Linux Standard Base (LSB), LSB Core - Generic. This module provides the fundamental system interfaces, libraries, and runtime environment upon which all conforming applications and libraries depend. LSB Core - Generic, the common part, should be used in conjunction with an architecture-specific part. Whenever a section of the common part is supplemented by architecture-specific information, the common part includes a reference to the architecture-specific part. Architecture-specific parts of the LSB Core Specification may also contain additional information that is not referenced in the common part. Interfaces described in this part of the LSB Core Specification are mandatory except where explicitly listed otherwise. Interfaces described in the LSB Core module are supplemented by other LSB modules. All other modules depend on the presence of LSB Core.
Noyau de base normalisé Linux (LSB) — Partie 1-2: Partie générique de la spécification du module de base "Core"
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Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 23360-1-2
First edition
2021-10
Linux Standard Base (LSB) —
Part 1-2:
Core specification generic part
Reference number
ISO/IEC 23360-1-2:2021(E)
©
ISO/IEC 2021
---------------------- Page: 1 ----------------------
ISO/IEC 23360-1-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2021
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
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 23360-1-2:2021(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 (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 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 the Linux Foundation as Linux Standard Base (LSB): Core specification
generic part and drafted in accordance with its editorial rules. It was assigned to Joint Technical
Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 22, Programming languages, their
environments and system software interfaces, and adopted by National Bodies.
This first edition of ISO/IEC 23360-1-2 cancels and replaces ISO/IEC 23360-1:2006, which has been
technically revised.
This document is based on “The GNU Free Documentation License, version 1.1”. The license is available
at https://www.gnu.org/licenses/old-licenses/fdl-1.1.html.
A list of all parts in the ISO/IEC 23660 series can be found on the ISO and IEC websites.
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 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC 23360-1-2:2021(E)
Contents
Foreword . iii
Introduction . vii
I Introductory Elements . 1
1 Scope . 2
2 References . 3
2.1 Normative References . 3
2.2 Informative References/Bibliography. 5
3 Requirements . 8
3.1 Relevant Libraries . 8
3.2 LSB Implementation Conformance. 8
3.3 LSB Application Conformance . 10
4 Terms and Definitions . 11
5 Documentation Conventions . 13
6 Relationship To ISO/IEC 9945 POSIX . 14
7 Relationship To Other Linux Foundation Specifications . 15
II Executable And Linking Format (ELF) . 16
8 Introduction . 17
9 Low Level System Information . 18
9.1 Operating System Interface . 18
9.2 Machine Interface . 18
10 Object Format . 19
10.1 Object Files . 19
10.2 Sections . 19
10.3 Special Sections . 23
10.4 Symbol Mapping . 29
10.5 DWARF Extensions . 29
10.6 Exception Frames . 31
10.7 Symbol Versioning . 36
10.8 ABI note tag . 40
11 Dynamic Linking . 41
11.1 Program Loading and Dynamic Linking . 41
11.2 Program Header . 41
11.3 Dynamic Entries . 41
12 C++ Class Representations . 46
12.1 C++ Data Representation. 46
13 Symbol Mapping . 50
13.1 Symbol Mapping . 50
III Base Libraries . 51
14 Base Libraries . 52
14.1 Introduction . 52
14.2 Program Interpreter . 52
14.3 Interfaces for libc . 52
14.4 Data Definitions for libc . 73
14.5 Interface Definitions for libc . 180
14.6 Interfaces for libm . 393
14.7 Data Definitions for libm . 397
14.8 Interface Definitions for libm . 403
14.9 Interfaces for libpthread . 428
14.10 Data Definitions for libpthread . 434
14.11 Interface Definitions for libpthread . 439
iv © 2021 ISO/IEC – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC 23360-1-2:2021(E)
14.12 Interfaces for libgcc_s . 444
14.13 Data Definitions for libgcc_s . 445
14.14 Interface Definitions for libgcc_s . 446
14.15 Interfaces for libdl . 452
14.16 Data Definitions for libdl. 453
14.17 Interface Definitions for libdl . 454
14.18 Interfaces for librt . 457
14.19 Data Definitions for librt . 459
14.20 Interfaces for libcrypt . 461
14.21 Data Definitions for libcrypt. 462
14.22 Interface Definitions for libcrypt . 462
14.23 Interfaces for libpam . 464
14.24 Data Definitions for libpam . 465
14.25 Interface Definitions for libpam . 467
IV Utility Libraries . 481
15 Utility Libraries . 482
15.1 Introduction . 482
15.2 Interfaces for libz . 482
15.3 Data Definitions for libz . 483
15.4 Interface Definitions for libz . 486
15.5 Interfaces for libncurses . 533
15.6 Data Definitions for libncurses . 538
15.7 Interface Definitions for libncurses . 546
15.8 Interfaces for libncursesw . 554
15.9 Data Definitions for libncursesw . 560
15.10 Interface Definitions for libncursesw . 587
15.11 Interfaces for libutil . 587
15.12 Data Definitions for libutil . 588
15.13 Interface Definitions for libutil . 588
V C++ Libraries . 594
16 Libraries . 595
16.1 Interfaces for libstdcxx . 595
16.2 Interface Definitions for libstdcxx . 850
VI Commands and Utilities . 851
17 Commands and Utilities . 852
17.1 Commands and Utilities . 852
17.2 Command Behavior . 853
VII Execution Environment . 917
18 File System Hierarchy . 918
18.1 /dev: Device Files . 918
18.2 /etc: Host-specific system configuration . 918
18.3 User Accounting Databases . 920
18.4 Path For System Administration Utilities . 920
19 Additional Recommendations . 921
19.1 Recommendations for applications on ownership and permissions . 921
20 Additional Behaviors . 923
20.1 Mandatory Optional Behaviors. 923
20.2 Optional Mandatory Behaviors. 924
20.3 Executable Scripts . 924
21 Localization . 926
21.1 Introduction . 926
© 2021 ISO/IEC – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC 23360-1-2:2021(E)
21.2 Regular Expressions . 926
21.3 Pattern Matching Notation . 926
VIII System Initialization . 928
22 System Initialization . 929
22.1 Cron Jobs . 929
22.2 Init Script Actions . 930
22.3 Comment Conventions for Init Scripts . 932
22.4 Installation and Removal of Init Scripts. 934
22.5 Run Levels . 935
22.6 Facility Names . 935
22.7 Script Names . 936
22.8 Init Script Functions . 936
IX Users & Groups . 939
23 Users & Groups . 940
23.1 User and Group Database . 940
23.2 User & Group Names . 940
23.3 User ID Ranges . 941
23.4 Rationale . 941
X Network Security Services . 942
24 Libraries . 943
24.1 Interfaces for libnspr4 . 943
24.2 Data Definitions for libnspr4 . 945
24.3 Interfaces for libnss3 . 955
24.4 Data Definitions for libnss3 . 956
24.5 Interfaces for libssl3 . 979
24.6 Data Definitions for libssl3 . 980
XI Package Format and Installation . 990
25 Software Installation . 991
25.1 Introduction . 991
25.2 Package File Format . 991
25.3 Package Script Restrictions . 1011
25.4 Package Tools . 1011
25.5 Package Naming Conventions . 1011
25.6 Package Dependencies . 1012
25.7 Package Architecture Considerations . 1013
Annex A Alphabetical Listing of Interfaces by Library . 1014
A.1 libc . 1014
A.2 libcrypt . 1029
A.3 libdl . 1029
A.4 libgcc_s . 1029
A.5 libm . 1029
A.6 libncurses . 1033
A.7 libncursesw . 1036
A.8 libpam . 1043
A.9 libpthread . 1043
A.10 librt . 1047
A.11 libutil . 1047
A.12 libz . 1048
A.13 libnspr4 . 1049
A.14 libnss3 . 1050
A.15 libssl3 . 1051
vi © 2021 ISO/IEC – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC 23360-1-2:2021(E)
Introduction
The LSB defines a binary interface for application programs that are compiled
and packaged for LSB-conforming implementations on many different hardware
architectures. A binary specification must include information specific to the
computer processor architecture for which it is intended. To avoid the complexity
of conditional descriptions, the specification has instead been divided into
generic parts which are augmented by one of several architecture-specific parts,
depending on the target processor architecture; the generic part will indicate
when reference must be made to the architecture part, and vice versa.
This document should be used in conjunction with the documents it references.
This document enumerates the system components it includes, but descriptions
of those components may be included entirely or partly in this document, partly
in other documents, or entirely in other reference documents. For example, the
section that describes system service routines includes a list of the system
routines supported in this interface, formal declarations of the data structures
they use that are visible to applications, and a pointer to the underlying
referenced specification for information about the syntax and semantics of each
call. Only those routines not described in standards referenced by this document,
or extensions to those standards, are described in the detail. Information
referenced in this way is as much a part of this document as is the information
explicitly included here.
The specification carries a version number of either the form x.y or x.y.z. This
version number carries the following meaning:
1. The first number (x) is the major version number. Versions sharing the same
major version number shall be compatible in a backwards direction; that is,
a newer version shall be compatible with an older version. Any deletion of
a library results in a new major version number. Interfaces marked as
deprecated may be removed from the specification at a major version
change.
2. The second number (y) is the minor version number. Libraries and
individual interfaces may be added, but not removed. Interfaces may be
marked as deprecated at a minor version change. Other minor changes may
be permitted at the discretion of the LSB workgroup.
3. The third number (z), if present, is the editorial level. Only editorial changes
should be included in such versions.
Since this specification is a descriptive Application Binary Interface, and not a
source level API specification, it is not possible to make a guarantee of 100%
backward compatibility between major releases. However, it is the intent that
those parts of the binary interface that are visible in the source level API will
remain backward compatible from version to version, except where a feature
marked as "Deprecated" in one rele
...
INTERNATIONAL ISO/IEC
STANDARD 23360-1-2
First edition
2021-08
Linux Standard Base (LSB) —
Part 1-2:
Core specification generic part
Reference number
ISO/IEC 23360-1-2:2021(E)
©
ISO/IEC 2021
---------------------- Page: 1 ----------------------
ISO/IEC 23360-1-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2021
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
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 23360-1-2:2021(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 (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 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 the Linux Foundation [as Linux Standard Base (LSB): Core specification
generic part] and drafted in accordance with its editorial rules. It was assigned to Joint Technical
Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 22, Programming languages, their
environments and system software interfaces, and adopted by National Bodies.
This first edition of ISO/IEC 23360-1-2 cancels and replaces ISO/IEC 23360-1:2006, which has been
technically revised.
A list of all parts in the ISO/IEC 23660 series can be found on the ISO and IEC websites.
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 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC 23360-1-2:2021(E)
Contents
Foreword . iii
Introduction . vii
I Introductory Elements . 1
1 Scope . 2
2 References . 3
2.1 Normative References . 3
2.2 Informative References/Bibliography. 5
3 Requirements . 8
3.1 Relevant Libraries . 8
3.2 LSB Implementation Conformance. 8
3.3 LSB Application Conformance . 10
4 Terms and Definitions . 11
5 Documentation Conventions . 13
6 Relationship To ISO/IEC 9945 POSIX . 14
7 Relationship To Other Linux Foundation Specifications . 15
II Executable And Linking Format (ELF) . 16
8 Introduction . 17
9 Low Level System Information . 18
9.1 Operating System Interface . 18
9.2 Machine Interface . 18
10 Object Format . 19
10.1 Object Files . 19
10.2 Sections . 19
10.3 Special Sections . 23
10.4 Symbol Mapping . 29
10.5 DWARF Extensions . 29
10.6 Exception Frames . 31
10.7 Symbol Versioning . 36
10.8 ABI note tag . 40
11 Dynamic Linking . 41
11.1 Program Loading and Dynamic Linking . 41
11.2 Program Header . 41
11.3 Dynamic Entries . 41
12 C++ Class Representations . 46
12.1 C++ Data Representation. 46
13 Symbol Mapping . 50
13.1 Symbol Mapping . 50
III Base Libraries . 51
14 Base Libraries . 52
14.1 Introduction . 52
14.2 Program Interpreter . 52
14.3 Interfaces for libc . 52
14.4 Data Definitions for libc . 73
14.5 Interface Definitions for libc . 180
14.6 Interfaces for libm . 393
14.7 Data Definitions for libm . 397
14.8 Interface Definitions for libm . 403
14.9 Interfaces for libpthread . 428
14.10 Data Definitions for libpthread . 434
14.11 Interface Definitions for libpthread . 439
iv © 2021 ISO/IEC – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC 23360-1-2:2021(E)
14.12 Interfaces for libgcc_s . 444
14.13 Data Definitions for libgcc_s . 445
14.14 Interface Definitions for libgcc_s . 446
14.15 Interfaces for libdl . 452
14.16 Data Definitions for libdl. 453
14.17 Interface Definitions for libdl . 454
14.18 Interfaces for librt . 457
14.19 Data Definitions for librt . 459
14.20 Interfaces for libcrypt . 461
14.21 Data Definitions for libcrypt. 462
14.22 Interface Definitions for libcrypt . 462
14.23 Interfaces for libpam . 464
14.24 Data Definitions for libpam . 465
14.25 Interface Definitions for libpam . 467
IV Utility Libraries . 481
15 Utility Libraries . 482
15.1 Introduction . 482
15.2 Interfaces for libz . 482
15.3 Data Definitions for libz . 483
15.4 Interface Definitions for libz . 486
15.5 Interfaces for libncurses . 533
15.6 Data Definitions for libncurses . 538
15.7 Interface Definitions for libncurses . 546
15.8 Interfaces for libncursesw . 554
15.9 Data Definitions for libncursesw . 560
15.10 Interface Definitions for libncursesw . 587
15.11 Interfaces for libutil . 587
15.12 Data Definitions for libutil . 588
15.13 Interface Definitions for libutil . 588
V C++ Libraries . 594
16 Libraries . 595
16.1 Interfaces for libstdcxx . 595
16.2 Interface Definitions for libstdcxx . 850
VI Commands and Utilities . 851
17 Commands and Utilities . 852
17.1 Commands and Utilities . 852
17.2 Command Behavior . 853
VII Execution Environment . 917
18 File System Hierarchy . 918
18.1 /dev: Device Files . 918
18.2 /etc: Host-specific system configuration . 918
18.3 User Accounting Databases . 920
18.4 Path For System Administration Utilities . 920
19 Additional Recommendations . 921
19.1 Recommendations for applications on ownership and permissions . 921
20 Additional Behaviors . 923
20.1 Mandatory Optional Behaviors. 923
20.2 Optional Mandatory Behaviors. 924
20.3 Executable Scripts . 924
21 Localization . 926
21.1 Introduction . 926
© 2021 ISO/IEC – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC 23360-1-2:2021(E)
21.2 Regular Expressions . 926
21.3 Pattern Matching Notation . 926
VIII System Initialization . 928
22 System Initialization . 929
22.1 Cron Jobs . 929
22.2 Init Script Actions . 930
22.3 Comment Conventions for Init Scripts . 932
22.4 Installation and Removal of Init Scripts. 934
22.5 Run Levels . 935
22.6 Facility Names . 935
22.7 Script Names . 936
22.8 Init Script Functions . 936
IX Users & Groups . 939
23 Users & Groups . 940
23.1 User and Group Database . 940
23.2 User & Group Names . 940
23.3 User ID Ranges . 941
23.4 Rationale . 941
X Network Security Services . 942
24 Libraries . 943
24.1 Interfaces for libnspr4 . 943
24.2 Data Definitions for libnspr4 . 945
24.3 Interfaces for libnss3 . 955
24.4 Data Definitions for libnss3 . 956
24.5 Interfaces for libssl3 . 979
24.6 Data Definitions for libssl3 . 980
XI Package Format and Installation . 990
25 Software Installation . 991
25.1 Introduction . 991
25.2 Package File Format . 991
25.3 Package Script Restrictions . 1011
25.4 Package Tools . 1011
25.5 Package Naming Conventions . 1011
25.6 Package Dependencies . 1012
25.7 Package Architecture Considerations . 1013
Annex A Alphabetical Listing of Interfaces by Library . 1014
A.1 libc . 1014
A.2 libcrypt . 1029
A.3 libdl . 1029
A.4 libgcc_s . 1029
A.5 libm . 1029
A.6 libncurses . 1033
A.7 libncursesw . 1036
A.8 libpam . 1043
A.9 libpthread . 1043
A.10 librt . 1047
A.11 libutil . 1047
A.12 libz . 1048
A.13 libnspr4 . 1049
A.14 libnss3 . 1050
A.15 libssl3 . 1051
vi © 2021 ISO/IEC – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC 23360-1-2:2021(E)
Introduction
The LSB defines a binary interface for application programs that are compiled
and packaged for LSB-conforming implementations on many different hardware
architectures. A binary specification must include information specific to the
computer processor architecture for which it is intended. To avoid the complexity
of conditional descriptions, the specification has instead been divided into
generic parts which are augmented by one of several architecture-specific parts,
depending on the target processor architecture; the generic part will indicate
when reference must be made to the architecture part, and vice versa.
This document should be used in conjunction with the documents it references.
This document enumerates the system components it includes, but descriptions
of those components may be included entirely or partly in this document, partly
in other documents, or entirely in other reference documents. For example, the
section that describes system service routines includes a list of the system
routines supported in this interface, formal declarations of the data structures
they use that are visible to applications, and a pointer to the underlying
referenced specification for information about the syntax and semantics of each
call. Only those routines not described in standards referenced by this document,
or extensions to those standards, are described in the detail. Information
referenced in this way is as much a part of this document as is the information
explicitly included here.
The specification carries a version number of either the form x.y or x.y.z. This
version number carries the following meaning:
1. The first number (x) is the major version number. Versions sharing the same
major version number shall be compatible in a backwards direction; that is,
a newer version shall be compatible with an older version. Any deletion of
a library results in a new major version number. Interfaces marked as
deprecated may be removed from the specification at a major version
change.
2. The second number (y) is the minor version number. Libraries and
individual interfaces may be added, but not removed. Interfaces may be
marked as deprecated at a minor version change. Other minor changes may
be permitted at the discretion of the LSB workgroup.
3. The third number (z), if present, is the editorial level. Only editorial changes
should be included in such versions.
Since this specification is a descriptive Application Binary Interface, and not a
source level API specification, it is not possible to make a guarantee of 100%
backward compatibility between major releases. However, it is the intent that
those parts of the binary interface that are visible in the source level API will
remain backward compatible from version to version, except where a feature
marked as "Deprecated" in one release may be removed from a future release.
Implementors are strongly encouraged to make use of symbol versioning to
permit simultaneous support of applications
...
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