Identification
Identification is the rule-compliant proof that a found ball really is yours.
Identification is one of the oldest duties in golf. Anyone who finds a ball in the rough or under leaves must be sure it is their own before playing on. If you play a wrong ball, in stroke play you face two penalty strokes. The rules therefore allow you to pick the ball up and turn it over to examine it — strictly following the procedure. You mark the position, lift it, clean it only as much as needed to recognize it and replace it exactly.
In practice it goes like this: your ball has flown towards the tree line and two balls lie close together there. You mark one with a tee, pick it up and recognize your identification mark. Without your own mark it becomes difficult if your playing partner plays the same brand and number. That is exactly why every rules evening recommends marking the ball before the round, for example with a dot or a line pattern. In case of doubt the ball counts as lost if you cannot clearly identify it as yours.
A typical mistake is picking the ball up without marking it and cleaning it generously. Anyone who simply lifts the ball and polishes it clean incurs a penalty stroke — even though the intention was honest. Also popular: rotating the ball in place with the clubhead without picking it up. That is allowed as long as you do not move it in the process. Announce the check briefly to your playing partners and there will never be any discussions.
FAQ
Am I allowed to pick up a ball in the rough to check whether it is mine?
Yes, the rules expressly allow it — but strictly following the procedure. You mark the position, lift the ball, clean it only as much as needed to recognize it and replace it exactly. Announce the check briefly to your playing partners and there will never be any discussions.
What happens if I accidentally play on with someone else's ball?
In stroke play you face two penalty strokes, because playing a wrong ball is a breach of the rules. That is exactly why identification is so important: if two balls lie close together, you must be sure which one is yours. In case of doubt the ball counts as lost if you cannot clearly identify it as yours.
How do I avoid confusion if my playing partner plays the same brand of ball?
Mark your ball before every round with your own mark, such as a dot or a line pattern — every rules evening recommends it. It also helps to briefly announce brand and number to your flight at the tee. Without your own marking, it becomes almost impossible to identify the ball reliably when brand and number are the same.