Understanding the WINS > NetBIOS name in SystemPrefs

Where does this name come from? And can I (safely) change it in System Prefs?

When I look on the *Network > Ethernet > Advanced > WINS* tab there is greyed-out name in the *NetBIOS Name* field. Where does this name come from? It does not match the Computer Name that I entered in *System Prefs > Sharing.*

I have an all-Mac network, running OS X on each Mac (10.6, 10.5, 10.4, 10.3) and a Verizon Actiontec MI424WR Rev C router. Does the router hand out the NetBIOS name along with the IP address when the Mac logs on to the network?

The names that appear in the NetBIOS Name field are generally the following:
new
new-host
new-host-3
new-host-4
(etc)

Interestingly, I experimented with the router admin and (in the router) renamed my 24" iMac (currently my only Snow-Leopard machine) to MartinsiMac24 and that is now the name that appears in the WINS > NetBIOS name field. Although I could not find any info in the documentation, I suspect the router assigns the NetBIOS names and when I changed it for my 24" iMac, it 'assigned' the new name to the MacAddress (Ethernet ID) of my Snow Leopard machine and that's how it shows up in the WINS > NetBIOS name field. Is my guess correct?