standards.7: Correct various details in the explanation of XPG/POSIX/SUS

As reported by mail from Geoff Clare, there are some details that
need correcting:

Subject: standards(7) (was: man-pages-5.07 released)
Date: Wed, 10 Jun 2020 10:53:14 +0100
From: Geoff Clare <gwc@opengroup.org>

...

The first isn't really a problem, just an oddity. You list
POSIX.1b as "formerly known as POSIX.4", but you don't do the
equivalent for POSIX.1c ("formerly known as POSIX.4a").

There are several problems with the XPG3 entry:

    "first significant release" - although I suppose XPG3 could
    be considered more significant than XPG2 because it was the
    first one to incorporate POSIX.1, I don't think it's fair to
    imply that XPG2 was not significant.  (E.g. XPG2 was
    significant in that it was the first release to include
    I18N, and the first that had a conformance test suite.)

    "produced by the X/Open Company, a multivendor consortium" -
    this conflates two different things called X/Open. X/Open
    Company Limited is the UK company that did the editing work,
    organised meetings, etc. X/Open Group is the consortium
    whose members developed the technical content.

    "This multivolume guide was based on the POSIX standards" -
    at the time there was only one POSIX standard, namely
    POSIX.1-1988.  The first release to incorporate POSIX.2 was
    XPG4 (which you may consider worth noting in the XPG4
    entry).

To fix these problems I would suggest changing the entry to:

XPG3  Released in 1989, this was the first release of the X/Open
      Portability Guide to be based on a POSIX standard
      (POSIX.1-1988).  This multivolume guide was developed by the
      X/Open Group, a multivendor consortium.

Under SUSv2 I would suggest changing:

    Sometimes also referred to as XPG5.

to:

    Sometimes also referred to (incorrectly) as XPG5.

Under POSIX.1-2001, SUSv3: "XSI conformance constitutes the Single
UNIX Specification version 3 (SUSv3)" is problematic.  I think I
touched on this in the previous discussion. I would suggest
deleting that sentence and instead inserting, before "Two
Technical Corrigenda ...", the following:

    The Single UNIX Specification version 3 (SUSv3) comprises the
    Base Specifications containing XBD, XSH, XCU and XRAT as
    above, plus X/Open Curses Issue 4 version 2 as an extra volume
    that is not in POSIX.1-2001.

Something similar is needed in the POSIX.1-2008, SUSv4 entry where
it talks about "the same four parts". The extra volume this time
is X/Open Curses Issue 7.
]]

Cowritten-by: Geoff Clare <gwc@opengroup.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man7/standards.7 b/man7/standards.7
index 1ba5511791012ef34594cd87a4c4262b96b1c863..9692519d0003722de2bb0166772f6d437de84225 100644 (file)
--- a/man7/standards.7
+++ b/man7/standards.7
@@ -138,10 +138,10 @@ describing real-time facilities
 for portable operating systems, ratified by ISO in 1996
 .RI ( "ISO/IEC 9945-1:1996" ).
 .TP
-.B POSIX.1c
+.B POSIX.1c " (formerly known as \fIPOSIX.4a\fP)"
 IEEE Std 1003.1c-1995, which describes the POSIX threads interfaces.
 .TP
-.B POSIX.1d
+.BR POSIX.1d
 IEEE Std 1003.1c-1999, which describes additional real-time extensions.
 .TP
 .B POSIX.1g
@@ -154,14 +154,14 @@ IEEE Std 1003.1j-2000, which describes advanced real-time extensions.
 A 1996 revision of POSIX.1 which incorporated POSIX.1b and POSIX.1c.
 .TP
 .B XPG3
-Released in 1989, this was the first significant release of the
-.IR "X/Open Portability Guide" ,
-produced by the
-X/Open Company, a multivendor consortium.
-This multivolume guide was based on the POSIX standards.
+Released in 1989, this was the first release of the X/Open
+Portability Guide to be based on a POSIX standard (POSIX.1-1988).
+This multivolume guide was developed by the X/Open Group,
+a multivendor consortium.
 .TP
 .B XPG4
 A revision of the X/Open Portability Guide, released in 1992.
+This revision incorporated POSIX.2.
 .TP
 .B XPG4v2
 A 1994 revision of XPG4.
@@ -180,7 +180,7 @@ Systems conforming to this standard can be branded
 .TP
 .B SUSv2
 Single UNIX Specification version 2.
-Sometimes also referred to as
+Sometimes also referred to (incorrectly) as
 .IR XPG5 .
 This standard appeared in 1997.
 Systems conforming to this standard can be branded
@@ -210,9 +210,6 @@ which additionally mandates a set of interfaces
 (the "XSI extension") which are only optional for POSIX conformance.
 XSI-conformant systems can be branded
 .IR "UNIX 03" .
-(XSI conformance constitutes the
-.I "Single UNIX Specification version 3"
-.RI ( SUSv3 ).)
 .IP
 The POSIX.1-2001 document is broken into four parts:
 .IP
@@ -234,6 +231,11 @@ POSIX.1-2001 is aligned with C99, so that all of the
 library functions standardized in C99 are also
 standardized in POSIX.1-2001.
 .IP
+The Single UNIX Specification version 3 (SUSv3) comprises the
+Base Specifications containing XBD, XSH, XCU, and XRAT as above,
+plus X/Open Curses Issue 4 version 2 as an extra volume that is
+not in POSIX.1-2001.
+.IP
 Two Technical Corrigenda (minor fixes and improvements)
 of the original 2001 standard have occurred:
 TC1 in 2003
@@ -252,8 +254,13 @@ POSIX.1-2001 become mandatory in the 2008 revision of the standard.
 A few interfaces that are present in POSIX.1-2001 are marked
 as obsolete in POSIX.1-2008, or removed from the standard altogether.
 .IP
-The revised standard is broken into the same four parts as POSIX.1-2001,
-and again there are two levels of conformance: the baseline
+The revised standard is structured in the same way as its predecessor.
+The Single UNIX Specification version 4 (SUSv4) comprises the
+Base Specifications containing XBD, XSH, XCU, and XRAT,
+plus X/Open Curses Issue 7 as an extra volume that is
+not in POSIX.1-2008.
+.IP
+Again there are two levels of conformance: the baseline
 .IR "POSIX Conformance" ,
 and
 .IR "XSI Conformance" ,