Thanx for pointing out "must" on my previous posting. Normally it is used to fine tune the sqlnet connection. There you would specify the tuning parameters like type of sql authentication that you would like to use, for names. in the case you are using the oracle names server.
So, I personally would consider it to be a must option, to preserve the consistency, over all installation. So, having it and leaving it off, is I presume an individuals choice.