"space" additionally place a space after the separator to make it
more readable. The B<sep_multiline> uses a linefeed character for
the RDN separator and a spaced B<+> for the AVA separator. It also
-indents the fields by four characters.
+indents the fields by four characters. If no field separator is specified
+then B<sep_comma_plus_space> is used by default.
=item B<dn_rev>