Information technology — Programming languages, their environments, and system software interfaces — Floating-point extensions for C — Part 1: Binary floating-point arithmetic

ISO/IEC TS 18661-1:2014 extends programming language C to support binary floating-point arithmetic conforming to ISO/IEC/IEEE 60559:2011. It covers all requirements of IEC 60559 as they pertain to C floating types that use IEC 60559 binary formats. ISO/IEC TS 18661-1:2014 does not cover decimal floating-point arithmetic, nor does it cover most optional features of IEC 60559. ISO/IEC TS 18661-1:2014 is primarily an update to IEC 9899:2011 (C11), normative Annex F (IEC 60559 floating-point arithmetic). However, it proposes that the new interfaces that are suitable for general implementations be added in the Library clauses of C11. Also it includes a few auxiliary changes in C11 where the specification is problematic for IEC 60559 support.

Technologies de l’information — Langages de programmation, leurs environnements et interfaces du logiciel système — Extensions à virgule flottante pour C — Partie 1: Arithmétique binaire en virgule flottante

General Information

Status
Published
Publication Date
20-Jul-2014
Current Stage
9093 - International Standard confirmed
Start Date
25-Nov-2018
Completion Date
14-Mar-2022
Ref Project

Buy Standard

Technical specification
ISO/IEC TS 18661-1:2014 - Information technology -- Programming languages, their environments, and system software interfaces -- Floating-point extensions for C
English language
52 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

TECHNICAL ISO/IEC
SPECIFICATION TS
18661-1
First edition
2014-07-15
Information technology — Programming
languages, their environments, and
system software interfaces — Floating-
point extensions for C —
Part 1:
Binary floating-point arithmetic
Technologies de l’information — Langages de programmation, leurs
environnements et interfaces du logiciel système — Extensions à
virgule flottante pour C —
Partie 1: Arithmétique binaire en virgule flottante
Reference number
ISO/IEC TS 18661-1:2014(E)
ISO/IEC 2014
---------------------- Page: 1 ----------------------
ISO/IEC TS 18661-1:2014(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2014

All rights reserved. Unless otherwise specified, 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
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2014 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC TS 18661-1:2014(E)
Contents Page

Introduction ......................................................................................................................................................... v

Background ..................................................................................................................................................... v

IEC 60559 floating-point standard ............................................................................................................ v

C support for IEC 60559 ............................................................................................................................ vi

Purpose ......................................................................................................................................................... vii

1 Scope ............................................................................................................................................................. 1

2 Conformance ................................................................................................................................................ 1

3 Normative references .................................................................................................................................. 1

4 Terms and definitions .................................................................................................................................. 2

5 C standard conformance ............................................................................................................................. 2

5.1 Freestanding implementations ................................................................................................................ 2

5.2 Predefined macros .................................................................................................................................... 2

5.3 Standard headers ...................................................................................................................................... 3

6 Revised floating-point standard ................................................................................................................. 5

7 Types ............................................................................................................................................................. 6

7.1 Terminology ............................................................................................................................................... 6

7.2 Canonical representation ......................................................................................................................... 7

8 Operation binding ........................................................................................................................................ 8

9 Floating to integer conversion .................................................................................................................. 13

10 Conversions between floating types and character sequences ......................................................... 13

10.1 Conversions with decimal character sequences ............................................................................... 13

10.2 Conversions to character sequences ................................................................................................. 14

11 Constant rounding directions ................................................................................................................. 15

12 NaN support .............................................................................................................................................. 22

13 Integer width macros ............................................................................................................................... 27

14 Mathematics ........................................................................................................................... 29

14.1 Nearest integer functions ..................................................................................................................... 29

14.1.1 Round to integer value in floating type ............................................................................................. 29

14.1.2 Convert to integer type ....................................................................................................................... 31

14.2 The llogb functions ............................................................................................................................. 34

14.3 Max-min magnitude functions ............................................................................................................. 35

14.4 The nextup and nextdown functions ................................................................................................. 36

14.5 Functions that round result to narrower type .................................................................................... 37

14.6 Comparison macros ............................................................................................................................. 40

14.7 Classification macros ........................................................................................................................... 41

14.8 Total order functions ............................................................................................................................ 43

14.9 Canonicalize functions ......................................................................................................................... 44

14.10 NaN functions ...................................................................................................................................... 45

15 The floating-point environment ............................................................................................ 47

15.1 The fesetexcept function .................................................................................................................. 47

15.2 The fetestexceptflag function ....................................................................................................... 48

15.3 Control modes ....................................................................................................................................... 48

16 Type-generic math ............................................................................................................. 50

Bibliography ...................................................................................................................................................... 52

© ISO/IEC 2014 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC TS 18661-1:2014(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. In the field of information

technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.

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).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,

as well as information about ISO's adherence to the WTO principles in the Technical Barriers to Trade (TBT)

see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/IEC JTC 1, Information technology, SC 22, Programming

languages, their environments, and system software interfaces.

ISO/IEC TS 18661 consists of the following parts, under the general title Information technology —

Programming languages, their environments, and system software interfaces — Floating-point extensions

for C:
 Part 1: Binary floating-point arithmetic
 Part 2: Decimal floating-point arithmetic
 Part 3: Interchange and extended types
 Part 4: Supplementary functions
 Part 5: Supplementary attributes

Part 1 updates ISO/IEC 9899:2011, Information technology — Programming languages — C, Annex F in

particular, to support all required features of ISO/IEC/IEEE 60559:2011, Information technology —

Microprocessor Systems — Floating-point arithmetic.

Part 2 supersedes ISO/IEC TR 24732:2009, Information technology — Programming languages, their

environments and system software interfaces — Extension for the programming language C to support

decimal floating-point arithmetic.

Parts 3-5 specify extensions to ISO/IEC 9899:2011 for features recommended in ISO/IEC/IEEE 60559:2011.

iv © ISO/IEC 2014 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC TS 18661-1:2014(E)
Introduction
Background
IEC 60559 floating-point standard

The IEEE 754-1985 standard for binary floating-point arithmetic was motivated by an expanding diversity in

floating-point data representation and arithmetic, which made writing robust programs, debugging, and moving

programs between systems exceedingly difficult. Now the great majority of systems provide data formats and

arithmetic operations according to this standard. The IEC 60559:1989 international standard was equivalent to

the IEEE 754-1985 standard. Its stated goals were:

1 Facilitate movement of existing programs from diverse computers to those that adhere to this

standard.

2 Enhance the capabilities and safety available to programmers who, though not expert in

numerical methods, may well be attempting to produce numerically sophisticated programs.

However, we recognize that utility and safety are sometimes antagonists.

3 Encourage experts to develop and distribute robust and efficient numerical programs that are

portable, by way of minor editing and recompilation, onto any computer that conforms to this

standard and possesses adequate capacity. When restricted to a declared subset of the

standard, these programs should produce identical results on all conforming systems.

4 Provide direct support for
a. Execution-time diagnosis of anomalies
b. Smoother handling of exceptions
c. Interval arithmetic at a reasonable cost
5 Provide for development of
a. Standard elementary functions such as exp and cos
b. Very high precision (multiword) arithmetic
c. Coupling of numerical and symbolic algebraic computation
6 Enable rather than preclude further refinements and extensions.
To these ends, the standard specified a floating-point model comprising:

formats – for binary floating-point data, including representations for Not-a-Number (NaN) and signed

infinities and zeros

operations – basic arithmetic operations (addition, multiplication, etc.) on the format data to compose a

well-defined, closed arithmetic system; also conversions between floating-point formats and decimal

character sequences, and a few auxiliary operations

context – status flags for detecting exceptional conditions (invalid operation, division by zero, overflow,

underflow, and inexact) and controls for choosing different rounding methods

The ISO/IEC/IEEE 60559:2011 international standard is equivalent to the IEEE 754-2008 standard for

floating-point arithmetic, which is a major revision to IEEE 754-1985.

The revised standard specifies more formats, including decimal as well as binary. It adds a 128-bit binary

format to its basic formats. It defines extended formats for all of its basic formats. It specifies data interchange

© ISO/IEC 2014 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC TS 18661-1:2014(E)

formats (which may or may not be arithmetic), including a 16-bit binary format and an unbounded tower of

wider formats. To conform to the floating-point standard, an implementation must provide at least one of the

basic formats, along with the required operations.

The revised standard specifies more operations. New requirements include – among others – arithmetic

operations that round their result to a narrower format than the operands (with just one rounding), more

conversions with integer types, more classifications and comparisons, and more operations for managing

flags and modes. New recommendations include an extensive set of mathematical functions and seven

reduction functions for sums and scaled products.

The revised standard places more emphasis on reproducible results, which is reflected in its standardization

of more operations. For the most part, behaviors are completely specified. The standard requires conversions

between floating-point formats and decimal character sequences to be correctly rounded for at least three

more decimal digits than is required to distinguish all numbers in the widest supported binary format; it fully

specifies conversions involving any number of decimal digits. It recommends that transcendental functions be

correctly rounded.

The revised standard requires a way to specify a constant rounding direction for a static portion of code, with

details left to programming language standards. This feature potentially allows rounding control without

incurring the overhead of runtime access to a global (or thread) rounding mode.

Other features recommended by the revised standard include alternate methods for exception handling,

controls for expression evaluation (allowing or disallowing various optimizations), support for fully reproducible

results, and support for program debugging.

The revised standard, like its predecessor, defines its model of floating-point arithmetic in the abstract. It

neither defines the way in which operations are expressed (which might vary depending on the computer

language or other interface being used), nor does it define the concrete representation (specific layout in

storage, or in a processor's register, for example) of data or context, except that it does define specific

encodings that are to be used for data that may be exchanged between different implementations that

conform to the specification.

IEC 60559 does not include bindings of its floating-point model for particular programming languages.

However, the revised standard does include guidance for programming language standards, in recognition of

the fact that features of the floating-point standard, even if well supported in the hardware, are not available to

users unless the programming language provides a commensurate level of support. The implementation’s

combination of both hardware and software determines conformance to the floating-point standard.

C support for IEC 60559

The C standard specifies floating-point arithmetic using an abstract model. The representation of a floating-

point number is specified in an abstract form where the constituent components (sign, exponent, significand)

of the representation are defined but not the internals of these components. In particular, the exponent range,

significand size, and the base (or radix) are implementation-defined. This allows flexibility for an

implementation to take advantage of its underlying hardware architecture. Furthermore, certain behaviors of

operations are also implementation-defined, for example in the area of handling of special numbers and in

exceptions.

The reason for this approach is historical. At the time when C was first standardized, before the floating-point

standard was established, there were various hardware implementations of floating-point arithmetic in

common use. Specifying the exact details of a representation would have made most of the existing

implementations at the time not conforming.

Beginning with ISO/IEC 9899:1999 (C99), C has included an optional second level of specification for

implementations supporting the floating-point standard. C99, in conditionally normative Annex F, introduced

nearly complete support for the IEC 60559:1989 standard for binary floating-point arithmetic. Also, C99’s

informative Annex G offered a specification of complex arithmetic that is compatible with IEC 60559:1989.

vi © ISO/IEC 2014 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC TS 18661-1:2014(E)

ISO/IEC 9899:2011 (C11) includes refinements to the C99 floating-point specification, though is still based on

IEC 60559:1989. C11 upgrades Annex G from “informative” to “conditionally normative”.

ISO/IEC TR 24732:2009 introduced partial C support for the decimal floating-point arithmetic in

ISO/IEC/IEEE 60559:2011. ISO/IEC TR 24732, for which technical content was completed while IEEE 754-

2008 was still in the later stages of development, specifies decimal types based on ISO/IEC/IEEE 60559:2011

decimal formats, though it does not include all of the operations required by ISO/IEC/IEEE 60559:2011.

Purpose

The purpose of ISO/IEC TS 18661 is to provide a C language binding for ISO/IEC/IEEE 60559:2011, based

on the C11 standard, that delivers the goals of ISO/IEC/IEEE 60559 to users and is feasible to implement. It is

organized into five Parts.

Part 1, this document, provides changes to C11 that cover all the requirements, plus some basic

recommendations, of ISO/IEC/IEEE 60559:2011 for binary floating-point arithmetic. C implementations

intending to support ISO/IEC/IEEE 60559:2011 are expected to conform to conditionally normative Annex F

as enhanced by the changes in Part 1.

Part 2 enhances ISO/IEC TR 24732 to cover all the requirements, plus some basic recommendations, of

ISO/IEC/IEEE 60559:2011 for decimal floating-point arithmetic. C implementations intending to provide an

extension for decimal floating-point arithmetic supporting ISO/IEC/IEEE 60559:2011 are expected to conform

to Part 2.

Part 3 (Interchange and extended types), Part 4 (Supplementary functions), and Part 5 (Supplementary

attributes) cover recommended features of ISO/IEC/IEEE 60559:2011. C implementations intending to provide

extensions for these features are expected to conform to the corresponding Parts.

© ISO/IEC 2014 – All rights reserved vii
---------------------- Page: 7 ----------------------
TECHNICAL SPECIFICATION ISO/IEC TS 18661-1:2014(E)
Information technology — Programming languages, their
environments, and system software interfaces — Floating-point
extensions for C —
Part 1:
Binary floating-point arithmetic
1 Scope

This part of ISO/IEC TS 18661 extends programming language C to support binary floating-point arithmetic

conforming to ISO/IEC/IEEE 60559:2011. It covers all requirements of IEC 60559 as they pertain to C floating

types that use IEC 60559 binary formats.

This part of ISO/IEC TS 18661 does not cover decimal floating-point arithmetic, nor does it cover most

optional features of IEC 60559.

This part of ISO/IEC TS 18661 is primarily an update to IEC 9899:2011 (C11), normative Annex F (IEC 60559

floating-point arithmetic). However, it proposes that the new interfaces that are suitable for general

implementations be added in the Library clauses of C11. Also it includes a few auxiliary changes in C11 where

the specification is problematic for IEC 60559 support.
2 Conformance
An implementation conforms to this part of ISO/IEC TS 18661 if

a) It meets the requirements for a conforming implementation of C11 with all the changes to C11 specified in

this part of ISO/IEC TS 18661; and
b) It defines __STDC_IEC_60559_BFP__ to 201404L.
3 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.

ISO/IEC 9899:2011, Information technology — Programming languages — C
ISO/IEC 9899:2011/Cor.1:2012, Technical Corrigendum 1

ISO/IEC/IEEE 60559:2011, Information technology — Microprocessor Systems — Floating-point arithmetic

(with identical content to IEEE 754-2008, IEEE Standard for Floating-Point Arithmetic. The Institute of

Electrical and Electronic Engineers, Inc., New York, 2008)
© ISO/IEC 2014 – All rights reserved 1
---------------------- Page: 8 ----------------------
ISO/IEC TS 18661-1:2014(E)
4 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/IEC 9899:2011,

ISO/IEC/IEEE 60559:2011 and the following apply.
4.1
C11

standard ISO/IEC 9899:2011, Information technology — Programming Languages — C, including Technical

Corrigendum 1 (ISO/IEC 9899:2011/Cor.1:2012)
5 C standard conformance
5.1 Freestanding implementations

The following change to C11 expands the conformance requirements for freestanding implementations so that

they might conform to this part of ISO/IEC TS 18661.
Change to C11:
Insert after the third sentence of 4#6:

The strictly conforming programs that shall be accepted by a conforming freestanding implementation

that defines __STDC_IEC_60559_BFP__ may also use features in the contents of the standard

headers and and the numeric conversion functions (7.22.1) of the standard

header . All identifiers that are reserved when is included in a hosted

implementation are reserved when it is included in a freestanding implementation.

5.2 Predefined macros

The following changes to C11 obsolesce __STDC_IEC_559__, the current conformance macro for Annex F,

in favor of __STDC_IEC_60559_BFP__, for consistency with other conformance macros and to distinguish its

application to binary floating-point arithmetic. The macro __STDC_IEC_559__ is retained as obsolescent, for

compatibility with existing programs.
Changes to C11:
In 6.10.8.3#1, before:

__STDC_IEC_559__ The integer constant 1, intended to indicate conformance to Annex F (IEC

60559 binary floating-point arithmetic).
insert:

__STDC_IEC_60559_BFP__ The integer constant 201404L, intended to indicate conformance to

Annex F (IEC 60559 binary floating-point arithmetic).
In 6.10.8.3#1, append to the __STDC_IEC_559__ item:
Use of this macro is an obsolescent feature.

The following changes to C11 obsolesce __STDC_IEC_559_COMPLEX__, the current conformance macro for

Annex G, in favor of __STDC_IEC_60559_COMPLEX__, for consistency with other conformance macros.

2 © ISO/IEC 2014 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/IEC TS 18661-1:2014(E)
Changes to C11:
In 6.10.8.3#1, after the __STDC_IEC_559__ item, insert the item:

__STDC_IEC_60559_COMPLEX__ The integer constant 201404L, intended to indicate conformance

to the specifications in annex G (IEC 60559 compatible complex arithmetic).
In 6.10.8.3#1, append to the __STDC_IEC_559_COMPLEX__ item:
Use of this macro is an obsolescent feature.
5.3 Standard headers

The new identifiers added to C11 library headers by this part of ISO/IEC TS 18661 are defined or declared by

their respective headers only if __STDC_WANT_IEC_60559_BFP_EXT__ is defined as a macro at the point

in the source file where the appropriate header is first included. The following changes to C11 list these

identifiers in each applicable library subclause.
Changes to C11:
After 5.2.4.2.1#1, insert the paragraph:

[1a] The following identifiers are defined only if __STDC_WANT_IEC_60559_BFP_EXT__ is defined

as a macro at the point in the source file where is first included:
CHAR_WIDTH USHRT_WIDTH ULONG_WIDTH
SCHAR_WIDTH INT_WIDTH LLONG_WIDTH
UCHAR_WIDTH UINT_WIDTH ULLONG_WIDTH
SHRT_WIDTH LONG_WIDTH
After 5.2.4.2.2#6, insert the paragraph:

[6a] The following identifier is defined only if __STDC_WANT_IEC_60559_BFP_EXT__ is defined as a

macro at the point in the source file where is first included:
CR_DECIMAL_DIG
After 7.6#3, insert the paragraph:

[3a] The following identifiers are defined or declared only if __STDC_WANT_IEC_60559_BFP_EXT__

is defined as a macro at the point in the source file where is first included:

femode_t fetestexceptflag
FE_DFL_MODE fegetmode
FE_SNANS_ALWAYS_SIGNAL fesetmode
fesetexcept
After 7.12#1, insert the paragraph:

[1a] The following identifiers are defined or declared only if __STDC_WANT_IEC_60559_BFP_EXT__

is defined as a macro at the point in the source file where is first included:

© ISO/IEC 2014 – All rights reserved 3
---------------------- Page: 10 ----------------------
ISO/IEC TS 18661-1:2014(E)
FP_INT_UPWARD FP_FAST_FSUBL
FP_INT_DOWNWARD FP_FAST_DSUBL
FP_INT_TOWARDZERO FP_FAST_FMUL
FP_INT_TONEARESTFROMZERO FP_FAST_FMULL
FP_INT_TONEAREST FP_FAST_DMULL
FP_LLOGB0 FP_FAST_FDIV
FP_LLOGBNAN FP_FAST_FDIVL
SNANF FP_FAST_DDIVL
SNAN FP_FAST_FFMA
SNANL FP_FAST_FFMAL
FP_FAST_FADD FP_FAST_DFMAL
FP_FAST_FADDL FP_FAST_FSQRT
FP_FAST_DADDL FP_FAST_FSQRTL
FP_FAST_FSUB FP_FAST_DSQRTL
iseqsig fmaxmagf ffmal
iscanonical fmaxmagl dfmal
issignaling fminmag fsqrt
issubnormal fminmagf fsqrtl
iszero fminmagl dsqrtl
fromfp nextup totalorder
fromfpf nextupf totalorderf
fromfpl nextupl totalorderl
ufromfp nextdown totalordermag
ufromfpf nextdownf totalordermagf
ufromfpl nextdownl totalordermagl
fromfpx fadd canonicalize
fromfpxf faddl canonicalizef
fromfpxl daddl canonicalizel
ufromfpx fsub getpayload
ufromfpxf fsubl getpayloadf
ufromfpxl dsubl getpayloadl
roundeven fmul setpayload
roundevenf fmull setpayloadf
roundevenl dmull setpayloadl
llogb fdiv setpayloadsig
llogbf fdivl setpayloadsigf
llogbl ddivl setpayloadsigl
fmaxmag ffma
After 7.20#4, insert the paragraph:

[4a] The following identifiers are defined only if __STDC_WANT_IEC_60559_BFP_EXT__ is defined

as a macro at the point in the source file where is first included:
INTN_WIDTH UINT_FASTN_WIDTH PTRDIFF_WIDTH
UINTN_WIDTH INTPTR_WIDTH SIG_ATOMIC_WIDTH
INT_LEASTN_WIDTH UINTPTR_WIDTH SIZE_WIDTH
UINT_LEASTN_WIDTH INTMAX_WIDTH WCHAR_WIDTH
INT_FASTN_WIDTH UINTMAX_WIDTH WINT_WIDTH
After 7.22#1, insert the paragraph:

[1a] The following identifiers are declared only if __STDC_WANT_IEC_60559_BFP_EXT__ is defined

as a macro at the point in the source file where is first included:
strfromd strfromf strfroml
4 © ISO/IEC 2014 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/IEC TS 18661-1:2014(E)
After 7.25#1, insert the paragraph:
[1a] The following identifiers are defined as type-generic macros only if

__STDC_WANT_IEC_60559_BFP_EXT__ is defined as a macro at the point in the source file where

is first included:
roundeven fromfpx fmul
llogb ufromfpx dmul
fmaxmag totalorder fdiv
fminmag totalordermag ddiv
nextup fadd ffma
nextdown dadd dfma
fromfp fsub fsqrt
ufromfp dsub dsqrt
6 Revised floating-point standard

C11 Annex F specifies C language support for the floating-point arithmetic of IEC 60559:1989. This document

proposes changes to C11 to bring Annex F into alignment with ISO/IEC/IEEE 60559:2011. The changes to

C11 below update the introduction to Annex F to acknowledge the revision to IEC 60559.

Changes to C11:
Change F.1 from:
F.1 Introduction
[1] This annex specifies C language support for the IE
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.