A fork of Rural Dictionary
When you delete all the digits of a phone number that you don't want to drunk dial/text/communicate with except the last 4 digits-Thereby if they text or call you, you are able to identify them without the awkwardness of asking them "who is this."
John - "Hey man, why dont you text Tina for a late night booty call, she was really hot." Evan - "Dude, she has a boyfriend who plays for the Vikings offensive line, I had to last four her to not get me in trouble. She can text me if she wants." John - "Wise decision."