Here's an interesting story from the Women's Australian Open.

Karrie Webb was accused of breaking a rule during play when a rules official saw her placing a tee behind her ball marker. The official didn't say anything to her at the time he saw her doing it.

After the round, and after she had finished checking her card with Christina Kim, the rules committee confronted her, saying that she had broken a rule using the tee. Webb asked them which rule...and they didn't know. They then called the R&A and found out that there is no rule against placing a tee behind the marker to help the player read a putt.

Needless to say, Webb was pretty steamed at the accusation and how it was handled. Being accused of cheating without knowing the rule is just a little embarrassing.

Interesting part of the article - they said that 70 percent of players do this, but I've never seen it. I've seen people use a tee to mark their ball, but never a coin with a tee behind it.