+.IP \fBpush_vlan\fR:\fIethertype\fR
+Push a new VLAN tag onto the packet. Ethertype is used as the the Ethertype
+for the tag. Only ethertype 0x8100 should be used. (0x88a8 which the spec
+allows isn't supported at the moment.)
+A priority of zero and the tag of zero are used for the new tag.
+.