We have 'sign in and sign out'. How about 'sign in and sign off'?
What is difference between 'sign out' and 'sign off'?
When you "sign out" you write your name and time you are leaving in a book (next to your name and time that you signed in) then leave. Visitors to a company often have to do this.
You could also "sign out" a book from a library in a similar manner.
"Sign off" is usually what a TV or radio announcer does when they are finished their story...when they say good-bye. It isn't written.