Creating a match in 5.4beta

So the basic to the bones code to start a server was this back on 5.3:
NM.matchMaker.CreateMatch(matchName, NM.matchSize, true, "", NM.OnMatchCreate);
but now it asks for a lot more eg.
string publicClientAddress, string privateClientAddress, int eloScoreForMatch, int requestDomain.
I understand the eloScoreForMatch feature, but what do I put in the spots for the other 3 new variables for creating a match?