The designation c/o is an abbreviation of the term care of which means take care of. It is listed on the first line of the street address in front of the name of the person handling the mail. Residents and those who sublet housing are not recommended to enter a c/o address. They should instead put their name directly on the door and on the post or property box at the entrance.
C/O should not be used in pickup addresses. Enter an alternative sender name instead.