--- The same as Cfg, except everything is optional. It's easy to merge
--- two of these by simply dropping the Nothings in favor of the Justs.
+-- | The same as Cfg, except everything is optional. It's easy to
+-- merge two of these by simply dropping the Nothings in favor of
+-- the Justs. The 'usernames' are left un-maybed so that cmdargs
+-- can parse more than one of them.
+--