- <listitem><para>Set POSIX ACLs (access control lists).
- Lines of this type accept shell-style globs in
- place of normal path names. This can be useful for
- allowing additional access to certain files.
- </para></listitem>
+ <term><varname>a+</varname></term>
+ <listitem><para>Set POSIX ACLs (access control lists). If
+ suffixed with <varname>+</varname>, specified entries will
+ be added to the existing set.
+ <command>systemd-tmpfiles</command> will automatically add
+ the required base entries for user and group based on the
+ access mode of the file, unless base entries already exist
+ or are explictly specified. The mask will be added if not
+ specified explicitly or already present. Lines of this type
+ accept shell-style globs in place of normal path names. This
+ can be useful for allowing additional access to certain
+ files.</para></listitem>