In addition to the normal parsing rules specified in the bf(chmod)(1)
manpage, you can specify an item that should only apply to a directory by
prefixing it with a 'D', or specify an item that should only apply to a
-file by prefixing it with a 'F'. For example:
+file by prefixing it with a 'F'. For example, the following will ensure
+that all directories get marked set-gid, that no files are other-writable,
+that both are user-writable and group-writable, and that both have
+consistent executability across all bits:
quote(--chmod=Dg+s,ug+w,Fo-w,+X)