Tony Thompson says:

"Um, Mike, the rules say (or used to say) that as long as your full name is in your email address, you are okay: and JIm Betz does have his full name there."

and, Jim apparently Betz says:

"Mike,

We've been around this corner before. My full name is in
my email address - there for any one who wants to see it.
Normally I post using the email interface. But my member
info is clearly available to anyone who wants/needs it.

- Jim (Betz)"

Well, the rules do state "If the member's address IS
their full name exactly [ to the left of an @ sign ] or simply their full
name, that is acceptable as a signature." I have to admit that there is an
implied understanding that the member's full name in the email address
is that displayed on both the Yahoo group's message list and that displayed
on the message as sent to the group owner [ me ]. In neither case is this true
in Jim's case. Yes, it IS available for anyone who wants to see it...if they take the trouble to dig it out. I will note that, in some cases, I have to guess who a message comes from. IOW, the "From" shows just Jim on the message sent to me by Yahoogroups and that is all that shows in the STMFC message list.

The issue of need for the last name in the message is not open to discussion.
I suppose there might be an analogy to a letter with a return address of one name...like Tom. On the inside, the sender might include his full name and
address. If it was in the sender's best interest to have the letter read,
however, I would believe the sender would make certain the containing envelope
had a name and an address on it. Having only Tom as an address would not tend to
encourage it being read.

Mike Brock...even I can remember my last name. Now, if someone's last name were Htzroptresdtrelz I might consider a request for an exception....particularly if they could pronounce it.