Do wild cards speak?

[maryfield48]

Hi,

I've been looking around online and haven't seen this question directly addressed. In the showdown in a game with wild cards does the player have to nominate what his wild card(s) represent, or does the table just formulate the best hand?

In the case at hand, a player made a flush with a natural K, and a wild card, and at the showdown called out "Flush, King high", when of course he should have nominated the wild card as an Ace. His opponent had an Ace high flush with no King, so it was the difference between winning & losing - what's the right decision?

Peter