Several manpages contain duplicate text describing a standard set of .d
configuration directories, with the usual sorting, precedence,
overrides, and so on. Factor this common text out using XInclude before
proliferating it even further.
An administrator might want to block a certain sysusers config file from
being executed, e.g. to block the creation of a certain user.
Only a relatively short description is added in the man page, since
overrides should be relatively rare.
Josh Triplett