-# Port 9100 is copied to /dev/lp0, 9101 to /dev/lp1 and 9102
-# to /dev/lp2. The default is port 9100 to /dev/lp0.
-# Values are 0|1|2
+# printing port list, in the form "number [options]"
+# where:
+# - number is the port number in the range [0-9]
+# the p910nd daemon will listen on tcp port 9100+number
+# - options can be :
+# -b to turn on bidirectional copying.
+# -f to specify a different printer device.