- seats. Returns an array of seat identifiers. The
- returned array and all strings it references need to
- be freed with the libc
- <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- call after use.</para>
-
- <para>Similar, <function>sd_get_sessions()</function> may
+ seats. Returns a <constant>NULL</constant> terminated array of seat
+ identifiers. The returned array and all strings it
+ references need to be freed with the libc
+ <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ call after use. Note that instead of an empty array
+ <constant>NULL</constant> may be returned and should be considered
+ equivalent to an empty array.</para>
+
+ <para>Similarly, <function>sd_get_sessions()</function> may