[groff] 09/31: [docs]: Shift discussion of `\~` portability.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit cc1af07711c7b8ea3a060b3b76c8353ddf270b1d
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Aug 13 03:38:46 2022 -0500

    [docs]: Shift discussion of `\~` portability.
    
    * doc/groff.texi (Request and Macro Arguments): Move from here...
      (Other Differences): ...to here.
    
    * man/groff_diff.7.man (Implementation differences):
    * tmac/groff_man.7.man.in (Portability): Sync with the above.
---
 doc/groff.texi          | 21 +++++++++++++++------
 man/groff_diff.7.man    | 35 +++++++++++++++++++++++++++++++++++
 tmac/groff_man.7.man.in | 25 +++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index c9e0a5403..7b407485c 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -6578,12 +6578,7 @@ solution, using escaped spaces, can be found in 
documents prepared for
 @acronym{AT&T} @code{troff}.  Nevertheless, it is not optimal in most
 situations, since @w{@samp{\ }} inserts a fixed-width, non-breaking
 space.  GNU @code{troff} provides the @code{\~} escape sequence to
-insert an adjustable, non-breaking space.@footnote{@code{\~} is also
-supported by Heirloom Doctools @code{troff} 050915 (September 2005),
-@code{mandoc} 1.9.5 (2009-09-21), and @code{neatroff} (since commit
-1c6ab0f6e, 2016-09-13), but not by Plan@tie{}9 @code{troff}, Solaris
-@code{troff}, or DWB @code{troff} or @code{onroff}.}
-@c as of this writing, 2022-08-12
+insert an adjustable, non-breaking space.
 
 @cindex @code{"}, in a macro argument
 @cindex double quote, in a macro argument
@@ -16667,6 +16662,20 @@ referred to it as a ``living fossil''.} should be 
migrated to another
 @node Other Differences, , Compatibility Mode, Implementation Differences
 @subsection Other Differences
 
+@code{groff} request names unrecognized by other @code{troff}
+implementations will likely be ignored; escape sequences that are
+@code{groff} extensions are liable to be formatted literally.
+@cindex @code{\~}, incompatibilities with @acronym{AT&T} @code{troff}
+For example, the adjustable, non-breaking escape sequence @code{\~}
+@c BEGIN Keep in sync with groff_diff(7) and groff_man_style(7).
+is also supported by Heirloom Doctools @code{troff} 050915 (September
+2005), @code{mandoc} 1.9.5 (2009-09-21), and @code{neatroff} (since
+commit 1c6ab0f6e, 2016-09-13), but not by Plan@tie{}9 @code{troff},
+Solaris @code{troff}, or Documenter's Workbench @code{troff}.
+@c as of this writing, 2022-08-12
+@c END Keep in sync with groff_diff(7) and groff_man_style(7).
+@xref{Manipulating Filling and Adjustment}.
+
 @cindex @code{\A}, incompatibilities with @acronym{AT&T} @code{troff}
 @cindex @code{\|}, incompatibilities with @acronym{AT&T} @code{troff}
 @cindex @code{\^}, incompatibilities with @acronym{AT&T} @code{troff}
diff --git a/man/groff_diff.7.man b/man/groff_diff.7.man
index 0c53f7d82..f760d924b 100644
--- a/man/groff_diff.7.man
+++ b/man/groff_diff.7.man
@@ -5157,6 +5157,41 @@ compatibility mode.
 .
 .P
 .I groff
+request names unrecognized by other
+.I troff \" generic
+implementations will likely be ignored;
+escape sequences that are
+.I groff
+extensions are liable to be formatted literally.
+.
+For example,
+the adjustable,
+non-breaking escape sequence
+.B \[rs]\[ti]
+.\" BEGIN Keep in sync with groff.texi node "Other Differences" and
+.\" groff_man_style(7).
+is also supported by Heirloom Doctools
+.I troff \" Heirloom
+050915 (September 2005),
+.I mandoc
+1.9.5 (2009-09-21),
+and
+.I neatroff
+(since commit 1c6ab0f6e,
+2016-09-13),
+but not by Plan\~9
+.IR troff , \" Plan 9
+Solaris
+.IR troff , \" Solaris
+or Documenter's Workbench
+.IR troff . \" DWB
+.\" as of this writing, 2022-08-12
+.\" END Keep in sync with groff.texi node "Other Differences" and
+.\" groff_man_style(7).
+.
+.
+.P
+.I groff
 does not allow the use of the escape sequences
 .BR \[rs]| ,
 .BR \[rs]\[ha] ,
diff --git a/tmac/groff_man.7.man.in b/tmac/groff_man.7.man.in
index 5eb6155bc..3c97f9001 100644
--- a/tmac/groff_man.7.man.in
+++ b/tmac/groff_man.7.man.in
@@ -2409,6 +2409,31 @@ CSTR\e\(ti#8 documents the B\e\(tilanguage.
 .RE
 .
 .
+.\" BEGIN Keep in sync with groff.texi node "Other Differences" and
+.\" groff_diff(7).
+.IP
+This escape sequence is a
+.I groff
+extension also supported by Heirloom Doctools
+.I troff \" Heirloom
+050915 (September 2005),
+.I mandoc
+1.9.5 (2009-09-21),
+and
+.I neatroff
+(since commit 1c6ab0f6e,
+2016-09-13),
+but not by Plan\~9
+.IR troff , \" Plan 9
+Solaris
+.IR troff , \" Solaris
+or Documenter's Workbench
+.IR troff . \" DWB
+.\" as of this writing, 2022-08-12
+.\" END Keep in sync with groff.texi node "Other Differences" and
+.\" groff_diff(7).
+.
+.
 .TP
 .B \e&
 Non-printing input break.