[groff] 03/11: [docs]: Correct claim re: ms(7)'s ".NH S".

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 85cd0195d8b2ce771cfe7d9b2d4044cc040977b6
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Oct 4 14:20:45 2021 +1100

    [docs]: Correct claim re: ms(7)'s ".NH S".
    
    [docs]: Correct erroneous claim: the ".NH S" extension to ms(7) comes
    from 4.2BSD, not GNU.
    
    See
    <https://www.tuhs.org/cgi-bin/utree.pl?file=4.2BSD/usr/lib/tmac/tmac.s>.
---
 ChangeLog           |  5 +++++
 doc/groff.texi      | 18 +++++++++---------
 doc/ms.ms           | 30 +++++++++++++++---------------
 tmac/groff_ms.7.man | 18 ++++++------------
 4 files changed, 35 insertions(+), 36 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8328b9f..a9114ff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2021-10-03  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       [docs]: Correct erroneous claim: the ".NH S" extension to ms(7)
+       comes from 4.2BSD, not GNU.
+
+2021-10-03  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * doc/ms.ms (Creating a table of contents): Sync with recent
        additions to groff_ms(7), expand, and heavily revise.
 
diff --git a/doc/groff.texi b/doc/groff.texi
index 4f46382..8b3d76f 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -3214,8 +3214,9 @@ as by calling @samp{.NH 1} and then @samp{.NH 1} as the 
next such call,
 Alternatively, a first argument of@tie{}@code{S} can be given, followed
 by integral arguments to number the levels of the heading explicitly.
 Further automatic numbering, if used, resumes using the specified
-heading level indices as their predecessors.  This feature is a GNU
-extension.
+heading level indices as their predecessors.
+@c Although undocumented in Tuthill's 4.2BSD ms.diffs paper...
+This feature is a Berkeley extension.
 @endDefmac
 
 An example may be illustrative.
@@ -4307,8 +4308,12 @@ Uppercase 
 @cindex @code{ms} macros, @code{groff} differences from @acronym{AT&T}
 @cindex @acronym{AT&T} @file{ms}, macro package differences
 
-This section lists the (minor) differences between the @code{groff}
-@file{ms} macros and @acronym{AT&T} @file{ms} macros.
+The @code{groff} @file{ms} macros are a complete re-implementation,
+using no original @acronym{AT&T} code.  Since they take advantage of the
+extended features in @code{groff}, they cannot be used with
+@acronym{AT&T} @code{troff}.  @code{groff} @file{ms} supports several
+features described above as Berkeley and Version 10 Research Unix
+extensions, and adds several of its own.
 
 @itemize @bullet
 @item
@@ -4376,11 +4381,6 @@ right adjust lines, but it doesn't work''.  In 
@code{groff} @file{ms},
 it does.
 
 @item
-@code{groff} @file{ms} handles @code{S} as the first argument to the
-@code{NH} macro specially, allowing alteration of the automatic heading
-numbering sequence.
-
-@item
 @code{groff} @file{ms} supports the @code{PN} register, but it is not
 necessary; you can access the page number via the usual @code{%}
 register and invoke the @code{af} request to assign a different format
diff --git a/doc/ms.ms b/doc/ms.ms
index d29cbd7..fcff898 100644
--- a/doc/ms.ms
+++ b/doc/ms.ms
@@ -951,7 +951,8 @@ Further automatic numbering,
 if used,
 resumes using the specified heading level indices as their predecessors.
 .
-This feature is a GNU extension.
+\" Although undocumented in Tuthill's 4.2BSD ms.diffs paper...
+This feature is a Berkeley extension.
 T}
 .TE
 .
@@ -2981,11 +2982,20 @@ Differences from AT&T
 .I ms
 .XE
 .LP
-This section lists the (minor) differences between the
+The
 .I "groff ms"
-macros and AT&T
-.I ms
-macros.
+macros are a complete re-implementation,
+using no original AT&T code.
+.
+Since they take advantage of the extended features in
+.I groff ,
+they cannot be used with AT&T
+.I troff .
+.
+.I "groff ms"
+supports several features described above as Berkeley and Version 10
+Research Unix extensions,
+and adds several of its own.
 .
 .
 .PP
@@ -3113,16 +3123,6 @@ it does.
 .
 .PP
 .I "groff ms"
-handles
-.CW S \[rq] \[lq]
-as the first argument to the
-.CW NH
-macro specially,
-allowing alteration of the automatic heading numbering sequence.
-.
-.
-.PP
-.I "groff ms"
 supports the
 .CW PN
 register,
diff --git a/tmac/groff_ms.7.man b/tmac/groff_ms.7.man
index 6a99702..bce46a6 100644
--- a/tmac/groff_ms.7.man
+++ b/tmac/groff_ms.7.man
@@ -765,7 +765,8 @@ Further automatic numbering,
 if used,
 resumes using the specified heading level indices as their predecessors.
 .
-This feature is a GNU extension.
+.\" Although undocumented in Tuthill's 4.2BSD ms.diffs paper...
+This feature is a Berkeley extension.
 .
 .
 .PP
@@ -1979,7 +1980,10 @@ Since they take advantage of the extended features in
 they cannot be used with AT&T
 .IR troff .
 .
-Other differences include:
+.I groff ms
+supports several features described above as Berkeley and Version 10
+Research Unix extensions,
+and adds several of its own.
 .
 .
 .IP \[bu] 3n
@@ -2163,16 +2167,6 @@ it does.
 .
 .IP \[bu]
 .I groff ms
-handles
-.RB \[lq] S \[rq]
-as the first argument to the
-.B NH
-macro specially,
-allowing alteration of the automatic heading numbering sequence.
-.
-.
-.IP \[bu]
-.I groff ms
 supports the
 .B PN
 register,