Official List Policy On Signature Files
This is taken from a post by Jeff Wasilko (list owner) - 2/15/1997
Don't Overdo Signatures. Signatures are nice, and many people can have a signature added to their postings automatically by placing it in a file called "$HOME/.signature". Don't overdo it. Signatures can tell the world something about you, but keep them short. A signature that is longer than the message itself is considered to be in bad taste. The main purpose of a signature is to help people locate you, not to tell your life story. Every signature should include at least your return address relative to a major, known site on the network and a proper domain-format address. Your system administrator can give this to you. Some news posters attempt to enforce a 4 line limit on signature files -- an amount that should be more than sufficient to provide a return address and attribution.