[groff] 02/05: [docs]: Add and clarify ms extension provenance.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 93496d45a846dc15bcb1f5e2ed13942738fadde3
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Oct 8 20:55:22 2021 +1100

    [docs]: Add and clarify ms extension provenance.
    
    * The QI register was not documented by Lesk 1978, but was by Tuthill
      1983.
    * Fix several errors arising from the macro index in Lesk 1978 being
      incomplete.  BD, QP, QS, and QE were all present in Version 7 Unix.
    * All of the TOC-related macros are from 4.2BSD.
    
    Also mark `L` argument to `DS` macro as optional.
---
 doc/groff.texi      | 23 +++++++++++------------
 doc/ms.ms           | 35 +++++++++++++++--------------------
 tmac/groff_ms.7.man | 32 ++++++++++++--------------------
 3 files changed, 38 insertions(+), 52 deletions(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index f2468e5..74685d0 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -2763,8 +2763,7 @@ Default: 0.3@dmn{v} (1@dmn{v} on low-resolution devices).
 
 @Defmpreg {QI, ms}
 Defines the indentation amount used on both sides of a paragraph set
-with the @code{QP} or between the @code{QS} and @code{QE} macros.  This
-is a Berkeley extension.
+with the @code{QP} or between the @code{QS} and @code{QE} macros.
 
 Effective: next paragraph.
 
@@ -3148,7 +3147,7 @@ specified again or a heading or different paragraphing 
macro is called.
 
 @Defmac {QP, , ms}
 Set a paragraph indented from both left and right margins by the amount
-stored in the @code{QI} register.  This is a Berkeley extension.
+stored in the @code{QI} register.
 @endDefmac
 
 @DefmacList {QS, , ms}
@@ -3156,8 +3155,7 @@ stored in the @code{QI} register.  This is a Berkeley 
extension.
 Begin (@code{QS}) and end (@code{QE}) a region where each paragraph is
 indented from both margins by the amount stored in the @code{QI}
 register.  The text between @code{QS} and @code{QE} can be structured
-further by use of other paragraphing macros.  These macros are GNU
-extensions.
+further by use of other paragraphing macros.
 @endDefmac
 
 @Defmac {XP, , ms}
@@ -3728,7 +3726,7 @@ begins a kept display of the layout specified in its 
first argument;
 non-kept displays are begun with dedicated macros corresponding to their
 layout.
 
-@DefmacList {DS, @t{L}, ms}
+@DefmacList {DS, [@t{L}], ms}
 @DefmacListEndx {LD, , ms}
 Begin (@code{DS}:@: kept) left-aligned display.
 @endDefmac
@@ -4101,6 +4099,8 @@ to override this behavior.  At the end of the document, 
call @code{TC}
 or @code{PX} to emit the table of contents; @code{TC} resets the page
 number to @samp{i} (Roman numeral one), and then calls @code{PX}.
 
+All of these macros are Berkeley extensions.
+
 @DefmacList {XS, [@Var{page-number}, ms}
 @DefmacItemx {XA, [@Var{page-number} [@Var{indentation}, ms}
 @DefmacListEndx {XE, , ms}
@@ -4404,12 +4404,6 @@ Displays are left-aligned by default, not indented.  In 
@acronym{AT&T}
 @file{ms}, it is synonymous with @samp{.DS L}.
 
 @item
-Block displays were not documented in the @acronym{AT&T} @file{ms}
-manual (Berkeley corrected this oversight), but Version@tie{}7 Unix
-@file{ms} supported them nevertheless, as does @code{groff} @file{ms}
-(this is thus only an @emph{apparent} difference).
-
-@item
 Right-aligned displays are available.  The @acronym{AT&T} @file{ms}
 manual observes that ``it is tempting to assume that @samp{.DS R} will
 right adjust lines, but it doesn't work''.  In @code{groff} @file{ms},
@@ -4436,6 +4430,11 @@ occasion for a default column width register.  Further, 
the @code{MINGW}
 register and the second argument to @code{MC} specify a @emph{minimum}
 space between columns, not the fixed gutter width of @acronym{AT&T}
 @file{ms}.
+
+@item
+The @acronym{AT&T} @file{ms} manual did not document the @code{QI}
+register, whereas Berkeley did; @code{groff} @file{ms} accordingly
+supports it.
 @end itemize
 
 @Defmpreg {GS, ms}
diff --git a/doc/ms.ms b/doc/ms.ms
index c4d7282..35776ec 100644
--- a/doc/ms.ms
+++ b/doc/ms.ms
@@ -795,8 +795,6 @@ _
 \&.QP  T{
 Set a paragraph indented from both left and right margins by
 .CW \[rs]n[QI] .
-.
-This macro and register are Berkeley extensions.
 T}
 _
 T{
@@ -816,8 +814,6 @@ The text between
 and
 .CW .QE
 can be structured further by use of other paragraphing macros.
-.
-These macros are GNU extensions.
 T}
 _
 \&.XP  T{
@@ -1930,7 +1926,7 @@ lf(CR) lf(CR) | lx .
 Display macro  Description
 With keep      Without keep
 _
-\&.DS L        \&.LD   Begin left-aligned display.
+\&.DS \f[R][\f[]L\f[R]]        \&.LD   Begin left-aligned display.
 \&.DS I \f[R][\,\f[I]indent\/\f[]]     \
 \&.ID \f[R][\,\f[I]indent\/\f[]]       T{
 Begin display indented by
@@ -2797,6 +2793,9 @@ and then calls
 .CW PX .
 .
 .
+.PP
+All of these macros are Berkeley extensions.
+.
 .TS
 box;
 cb cb
@@ -3093,21 +3092,6 @@ it is synonymous with
 .
 .
 .PP
-Block displays were not documented in the AT&T
-.I ms
-manual
-(Berkeley corrected this oversight),
-but Version\~7 Unix
-.I ms
-supported them nevertheless,
-as does
-.I "groff ms"
-(this is thus only an
-.I apparent
-difference).
-.
-.
-.PP
 Right-aligned displays are available.
 .
 The AT&T
@@ -3190,6 +3174,17 @@ not the fixed gutter width of AT&T
 .
 .
 .PP
+The AT&T
+.I ms
+manual did not document the
+.CW QI
+register,
+whereas Berkeley did;
+.I "groff ms"
+accordingly supports it.
+.
+.
+.PP
 The register
 .CW GS
 is set to\~1 by the
diff --git a/tmac/groff_ms.7.man b/tmac/groff_ms.7.man
index 5709653..8a23709 100644
--- a/tmac/groff_ms.7.man
+++ b/tmac/groff_ms.7.man
@@ -666,8 +666,6 @@ is called.
 Set a paragraph indented from both left and right margins by
 .BR \[rs]n[QI] .
 .
-This macro and register are Berkeley extensions.
-.
 .
 .TP
 .B .QS
@@ -686,8 +684,6 @@ and
 .B .QE
 can be structured further by use of other paragraphing macros.
 .
-These macros are GNU extensions.
-.
 .
 .TP
 .B .XP
@@ -1223,7 +1219,7 @@ layout.
 .
 .
 .TP
-.B .DS L
+.BR .DS \~[ L ]
 .TQ
 .B .LD
 Begin
@@ -2136,21 +2132,6 @@ it is synonymous with
 .
 .
 .IP \[bu]
-Block displays were not documented in the AT&T
-.I ms
-manual
-(Berkeley corrected this oversight),
-but Version\~7 Unix
-.I ms
-supported them nevertheless,
-as does
-.I groff ms
-(this is thus only an
-.I apparent
-difference).
-.
-.
-.IP \[bu]
 Right-aligned displays are available.
 .
 The AT&T
@@ -2231,6 +2212,17 @@ not the fixed gutter width of AT&T
 .
 .
 .IP \[bu]
+The AT&T
+.I ms
+manual did not document the
+.B QI
+register,
+whereas Berkeley did;
+.I "groff ms"
+accordingly supports it.
+.
+.
+.IP \[bu]
 The register
 .B GS
 is set to\~1 by the