Clarification on signature lines

What exactly is and is not allowed to be used in a signature line now that the rules have changed yet again.

I noticed that the majority of ladies have simply deleted their signature while others are the same as before.

I would appreciate a breakdown of do's and don'ts if it's not asking for too much.
Thanks in advance for moderator help.

Due to the nature of how this will have to be answered, I will answer this in the other place that you asked the same basic question.