The final list of 18 players and four alternate players, indicating the full
surname(s), full first name(s), popular name, name on the shirt, date of birth,
name and country of the club, position and passport number of each player,
and seven officials (per team in the men’s and women’s Tournaments) shall be
sent to LOCOG by midnight on 9 July 2012 (London local time) at the latest,
with a copy to the FIFA general secretariat
That's from FIFA's official Olympic guidelines DCFC :-)