As some one of you already know, today referee asked me to get rid of my scarf during the game. He said that it is illegal to wear it. I did some searching about it. I didn't find any information in UEFA rules about it. BUT, there is an article -
http://www.telegraph.co.uk/sport/football/competitions/premier-league/8303326/Fifa-consider-snood-ban-as-they-could-pose-a-potential-danger-to-players-necks.html - they say that it could be banned due to danger to neck during tackles :]
Sounds true... Will try to find what was the verdict about it. (But it's only in FA board meeting, dunno about FIFA or UEFA)