U1S1E1R1N1A1M3E1S1
11 points
USERNAMES is validvalid
USERNAME, an identifying sequence of characters used for logging on to a computer system [n]
USERNAME, an identifying sequence of characters used for logging onto a computer system [n]
USERNAME, an identifying sequence of characters used for logging on to a computer system [n]
USERNAME, an identifying sequence of characters used for logging onto a computer system [n]