marking ball

Question
i was in a match play event. my competion was on the green and i was chipping. i asked him to mark his ball and leave it. he said this was illegal. is he right. where can i find this answer in The Rules of Golf.

Answer
Thomas:  A follow up to my original answer which is this is out of my expertise.  I played in a Match Play event in our Section of the PGA, was in the same situation, and I asked my opponent to mark his ball and leave it.  I believe you have control over your opponents ball.  Because you were off the green and not on it, you had every right to do so.  I do not know where to find the answer in the rules book, I just know I had the right to ask him to mark it, but leave it.  You can take it from there.  My suggestion is to write or call the USGA and get your answer quickly.

Eddie Kilthau
PGA Member