- <varname>systemd-nspawn</varname> to
- test against a specific
- implementation. If multiple
- virtualization technologies are nested,
- only the innermost is considered. The
- test may be negated by prepending an
- exclamation mark.</para>
+ <varname>systemd-nspawn</varname>,
+ <varname>docker</varname> to test
+ against a specific implementation. See
+ <citerefentry><refentrytitle>systemd-detect-virt</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ for a full list of known
+ virtualization technologies and their
+ identifiers. If multiple
+ virtualization technologies are
+ nested, only the innermost is
+ considered. The test may be negated by
+ prepending an exclamation mark.</para>