Are fans able to stand at Champions League or Europa League games? I ask because I stumbled across this -- http://en.wikipedia.org/wiki/UEFA_stadium_categories -- which stated "no standing spectators allowed" for games played in "category four," in other words the main competition of the Champions League and the Europa League (plus the Champions League playoffs). Is this enforced? I understand them not allowing standing sections (terraces), but do they actually force people to stay seated for these games?