It may come as a surprise to some golfers that the Rules do not require them to notify their marker or fellow competitor, which ball they are playing before starting a hole, nor when they are substituting a ball under the Rules during play of the hole. All that is required by the Rules is that a player can positively identify their ball in play.That is not to suggest that a player should not inform those that they are playing with of the brand, number and any identifying marks on their ball; it is both good etiquette and the sensible thing to do, as it avoids any possible doubt that might arise when a ball is played out of sight. It is recommended that markers make it a practice to ask the player they are marking for to describe the ball they are playing; how else can they be sure that the ball that the player finishes the hole with is the same one that they started with, or with the one that they correctly substituted under the Rules during play of the hole?
The player is permitted to change the brand, condition and colour of any balls they use during a round, without restriction. They may also borrow balls from any source. This makes it all the more necessary that they inform the other players in their group each time they change the ball they put into play.
On a lighter note I tell the story of a retired senior who played his home course 3-4 times a week. He had a mental block on one particular hole, which led him to regularly slice his drive into the same area of deep rough to the right of the fairway. On one occasion, after a couple of minutes, he shouted to his fellow searchers that he had found his Titleist No. 1 ball. “How do you know it is yours?” responded his marker. “It has the same personal identification that I always use”, he responded. “You hit so many balls into this rough that it would need to have today’s date on it for you to be sure”, was the terse, unsympathetic reply! Now I am sure that most of us can identify with having a certain hole on the course that we seem to visit the wrong part of and yes we often do have a playing partner with the same sense of humour don’t we!