Interesting:
over-sized chip rule
(n phrase) The rule, enforced in many cardrooms, that, when responding to action, a player puts into the pot a single chip or bill with a denomination larger than the bet indicated at that juncture, but does not announce a raise, that player's action is ruled to have been only a call. The over-sized chip or bill rule also applies when more than one chip is necessary to call a bet, but the last chip might be construed as a raise. The preceding applies to all rounds in limit games. In no-limit games, on the first round, the opening bet made with an over-sized chip or bill on the first round is considered a call of the bring-in amount; on any succeeding round, the first bet is equal to the size of over-sized chip or bill, unless an announcement to the contrary is made....
Found here:
http://www.planetpoker.com/games/dictionary/