It's called a sig line. Give me a sec and I'll put it down for you back here on this post.

Go to the top of the page and click on "My Home". Scroll down to where it says "Personnel information, email.... and click on the edit. Then when the next screen pops up scroll down to "Signature" It can be no more than 100 spaces long. After you type what you want, scroll down to the very bottom of the page and hit "submit".