[groff] 12/23: [doc,man]: Clarify a few points.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 15f72410f6fec3f571131f015b7eff703b29970d
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Sep 30 03:05:42 2024 -0500

    [doc,man]: Clarify a few points.
    
    * Special characters can be built-in or user-defined.
    * groff doesn't itself provide fonts, but rather font descriptions.
    * groff_diff(7): Note saturating arithmetic.
---
 doc/groff.texi.in    |  7 ++++---
 man/groff_diff.7.man | 11 +++++++++--
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/doc/groff.texi.in b/doc/groff.texi.in
index f32ed902d..9c859da6f 100644
--- a/doc/groff.texi.in
+++ b/doc/groff.texi.in
@@ -12953,9 +12953,10 @@ termed @dfn{conditional expressions}.
 @table @code
 @item c @var{glyph}
 True if @var{glyph} is available, where @var{glyph} is an ordinary
-character, a special character @samp{\(@var{xx}} or @samp{\[@var{xxx}]},
-@samp{\N'@var{xxx}'}, or has been defined by any of the @code{char},
-@code{fchar}, @code{fschar}, or @code{schar} requests.
+character, a special character @samp{\(@var{xx}} or @samp{\[@var{xxx}]}
+(whether built-in or user-defined), @samp{\N'@var{xxx}'}, or has been
+defined by any of the @code{char}, @code{fchar}, @code{fschar}, or
+@code{schar} requests.
 
 @item d @var{name}
 True if a string, macro, diversion, or request called @var{name} exists.
diff --git a/man/groff_diff.7.man b/man/groff_diff.7.man
index 8af6217f8..b89f4ee18 100644
--- a/man/groff_diff.7.man
+++ b/man/groff_diff.7.man
@@ -149,7 +149,7 @@ can group text typefaces into
 .I families.
 For example,
 .I groff
-ships families containing each of the styles
+ships with support for families containing each of the styles
 .RB \[lq] R \[rq],
 .RB \[lq] I \[rq],
 .RB \[lq] B \[rq],
@@ -563,6 +563,12 @@ if
 is empty.
 .
 .
+.P
+Arithmetic in GNU
+.I troff \" troff
+saturates instead of wrapping.
+.
+.
 .\" ====================================================================
 .SS "Conditional expressions"
 .\" ====================================================================
@@ -586,7 +592,8 @@ where
 .I chr
 is an ordinary character
 (Unicode basic Latin excluding control characters and the space),
-a special character,
+a special character
+(whether built-in or user-defined),
 or
 .BI \[rs]N\[aq] index\c
 .BR \[aq] .