Network Names

I thought I knew clustering and SQL fairly well but I was recently presented with a question to which I am finding conflicting answers. 

In a 2 node SQL cluster, what is the minimum number of network names that must be created?  Some say 3 (cluster name plus the names of the 2 nodes) and some say 5 (in addition to the first 3, the instance of SQL on each node must be named).  Can anyone tell me which is correct?

Thanks

Bert