diff --git a/doc/lxc.container.conf.sgml.in b/doc/lxc.container.conf.sgml.in
index 97f88995b..7b0099d3a 100644
--- a/doc/lxc.container.conf.sgml.in
+++ b/doc/lxc.container.conf.sgml.in
@@ -474,6 +474,12 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
options.
Several lines specify several routes.
The route is in format x.y.z.t/m, eg. 192.168.1.0/24.
+
+ In mode untagged VLAN membership can be set with the
+ option. It accepts a special value of 'none' indicating
+ that the container port should be removed from the bridge's default untagged VLAN.
+ The option can be specified multiple times to set
+ the container's bridge port membership to one or more tagged VLANs.