If the packet does already contain an MPLS label, pushes a new
outermost label as a copy of the existing outermost label.
.IP
-There are some limitations in the implementation. \fBpush_mpls\fR
-followed by another \fBpush_mpls\fR will result in the first
-\fBpush_mpls\fR being discarded.
+A limitation of the implementation is that processing of actions will stop
+if \fBpush_mpls\fR follows another \fBpush_mpls\fR unless there is a
+\fBpop_mpls\fR in between.
.
.IP \fBpop_mpls\fR:\fIethertype\fR
Strips the outermost MPLS label stack entry.
Currently the implementation restricts \fIethertype\fR to a non-MPLS Ethertype
and thus \fBpop_mpls\fR should only be applied to packets with
-an MPLS label stack depth of one.
-.
-.IP
-There are some limitations in the implementation. \fBpop_mpls\fR
-followed by another \fBpush_mpls\fR without an intermediate
-\fBpush_mpls\fR will result in the first \fBpush_mpls\fR being
-discarded.
+an MPLS label stack depth of one. A further limitation is that processing of
+actions will stop if \fBpop_mpls\fR follows another \fBpop_mpls\fR unless
+there is a \fBpush_mpls\fR in between.
.
.IP \fBmod_dl_src\fB:\fImac\fR
Sets the source Ethernet address to \fImac\fR.