+=item B<identifier=>I<E<lt>idE<gt>>
+
+If this option is present, only the data specified by the specified identifier
+(see below) will be flushed. Note that this option is not supported by all
+plugins (e.E<nbsp>g., the C<network> plugin does not support this).
+
+=back
+
+The B<plugin> and B<identifier> options may be specified more than once. In
+that case, all combinations of specified plugins and identifiers will be
+flushed only.
+
+=item B<listval>
+
+Returns a list of all values (by their identifier) available to the
+C<unixsock> plugin. Each value is printed on its own line. I.E<nbsp>e., this
+command returns a list of valid identifiers that may be used with the other
+commands.
+
+=item B<putval> I<E<lt>identifierE<gt>> [B<interval=>I<E<lt>secondsE<gt>>]
+I<E<lt>value-list(s)E<gt>>
+
+Submit one or more values (identified by I<E<lt>identifierE<gt>>, see below)
+to the daemon which will then dispatch them to the write plugins. B<interval>
+specifies the interval (in seconds) used to collect the values following that
+option. It defaults to the default of the running collectd instance receiving
+the data. Multiple I<E<lt>value-list(s)E<gt>> (see below) may be specified.
+Each of them will be submitted to the daemon. The values have to match the
+data-set definition specified by the type as given in the identifier (see
+L<types.db(5)> for details).
+
+=back
+
+=head1 IDENTIFIERS
+
+An identifier has the following format: