* src/ls.c (usage) [--group-directories-first]: Improve description.
* doc/coreutils.texi (Which files are listed): Likewise.
(see --sort option).
That is, this option specifies a primary sort key,
and the --sort option specifies a secondary key.
+However, any use of @option{--sort=none}
+(@option{-U}) disables this option altogether.
@item --hide=PATTERN
@opindex --hide=@var{pattern}
"), stdout);
fputs (_("\
--group-directories-first\n\
- group directories before files\n\
+ group directories before files.\n\
+ augment with a --sort option, but any\n\
+ use of --sort=none (-U) disables grouping\n\
"), stdout);
fputs (_("\
-G, --no-group in a long listing, don't print group names\n\