You should be able to use any name that is in the /etc/services file. And if there isn't a name in /etc/services for a port that you use for a specific task just add the port and name for the service in that file. That file is used by many TCP/IP programs to give useful names instead of port numbers (netstat output uses names from /etc/services for instance).
NetBIOS itself does not use ports. NetBIOS is actually not a protocol at all but requires a networking protocol to be encapsulated in. It can be encapsulated in NetBEUI or TCP/IP. The three common NetBIOS over TCP/IP ports are 137, 138, and 139. 137 is the NETBIOS Name Service, 138 is the NETBIOS Datagram Service and 139 is the NETBIOS session service (you should see these listed in the comments field in /etc/services). To get more detailed information about what sort of communiction goes on over those ports search the net, there's plenty of information out there on the subject.