What's your 20?

 Asks for your current location or whereabouts.

Origin and Meaning

• The Source: It comes from 10-codes, which are official radio signals used by law enforcement and citizens band (CB) radio operators.
• The Code: The full phrase is "10-20," which stands for "location."
• The Drop: Over time, speakers dropped the "10" in casual conversation, leaving just 'What's your 20?'

Usage

• I'm at the main entrance of the mall, what's your 20?
• My 20 is at home.