This rules depend from casino to casino and from tournament for tournament. Normally, you dont have the right to share any information about your holecards, as giving such information can be seen as colluding. One similar example was seen ,performed by a top pro in the recent WSOP - the player checked behind his royal flush on the river(he forgot his J was :heart

,and its forbidden to check behind the absolute nuts on the river, as this clearly helps the other player.
My personal advice, simply dont talk during a hand. Just dont.