The port may be specified either symbolically, e.g. ``hylafax''
or numerically.
This flag may be specified multiple times to request service on multiple
-different ports.
+different ports. Each time this flag is specified, it will listen on the
+specified port, bound to the last
+.BI \-l " bindaddress"
+specified. If no
+.BI \-l " bindaddress"
+was specified, it will bind to the system configured default wildcard
+address, which could be any of IPv6, or IPv4, or both.
.TP 10
.BI \-s " port"
Listen on the specified