* man/chmod.x: Mention -6000 too. Use .BR to fix trailing period.
and
.BR g\-s .
To clear these bits for directories with a numeric mode requires
-an additional leading zero, or leading = like
-.B 00755
-, or
-.B =755 .
+an additional leading zero like
+.BR 00755 ,
+leading minus like
+.BR \-6000 ,
+or leading equals like
+.BR =755 .
.SH "RESTRICTED DELETION FLAG OR STICKY BIT"
The restricted deletion flag or sticky bit is a single bit, whose
interpretation depends on the file type. For directories, it prevents