If an acronym is defined here, you may use it in normal conversation and expect anyone to know it. Feel free to add any of our language to this.
- easy like a piece of cake (AP Chem)
- execute the eat system call (has variations, such as "sleep") (Conversations with David)
When used in email subjects, indicates that there is no text of interest in the body of the email, so that the subject should be read carefully, and you don't need to take the time to look at the (empty) body. A "Re: " cancels this tag.