Golf Etique

Question
In a golf round, often another players caddy will run across the green to mark his players ball, when i am about to chip on to the green, the ball is nowhere near my line and it is very irritating, what the ruling on this?
Thanks
John

Answer
John,
I did brief search through the USGA Site.

First and foremost this applies: No Disturbance or Distraction

Players should always show consideration for other players on the course and should not disturb their play by moving, talking or making unnecessary noise.

This is under conduct of play. no rulings but a start. If the ball was to come into contact with another players ball then there are ruling for that.

Additionally under caddies: the caddie and player are responsible to know ALL the rule of golf.

If it was tournament play you could in my opinion protest to a rules official. however I dont believe there would be a penalty