Formula to return User Name from Created By

Jiri

Is there a formula to return User Name from Created By?

Mark.poole

create a reference sheet that had the username and the email. The. Use index match formula to pull the user name

Jiri

This is very cumbersome, because first one has to create the list of users; second one have to add new users into that list. (I have actually done that)

It would be much more efficient if I could get the User Name from record creator column/field.