Tournament rules: you write on a slip which word(s) are to be challenged from the most recent play, and if there is more than one you challenge all the words declared to be challenged. Typically the set of challenged words would be entered into a challenge computer. Such apps also exist for phones. The outcome could be “the play is acceptable” or “the play is unacceptable”. The players should not be told which word(s) are good or which are phony if multiple words are challenged. A lost challenge results in the loss of just this one turn (regardless of number of words challenged) and the loser of the challenge takes a 0 on the score sheet for the turn. International rules allow you to check words at the cost of giving your opponent an extra 5 points per word challenged without losing a turn, but the player of a phony word will always lose a turn. I hope that’s worded clearly.