Support
Support is any physical help or shielding that gives you an advantage during the stroke — and it is against the rules during the stroke.
The rules draw a clear line: while you make the stroke, no person may support or shield you and no object may protect you from wind or rain. The famous case is the umbrella that the caddie holds over you while you putt. That is forbidden and costs penalty strokes. Between strokes, on the other hand, the caddie may hold the umbrella. The underlying idea: the stroke is your performance alone — golf is a self-reliant sport without protective walls. The whole thing is distinguished from artificial devices, that is devices such as rangefinders, which have their own rules.
An everyday example: heavy rain, you are standing on the green. Your playing partner kindly holds an umbrella over your head while you play your approach. Exactly at that moment the forbidden support comes into being. Correct is: umbrella away or held by yourself, play the stroke, then back under cover. The same applies if someone wants to hold you steady on uneven ground so that you do not slip — that is only allowed as long as no stroke is being made.
The widespread misconception concerns the difference from permitted help. Trolley, gloves, tee or the umbrella between strokes are completely legitimate. The caddie may also advise you and search for the ball. It only becomes forbidden when a person or a thing physically stabilises you during the stroke or protects you from the elements. If in doubt, the simple rule of thumb applies: during the stroke you stand alone in the weather.
FAQ
May your caddie hold the umbrella for you while you putt?
No, that is exactly the famous forbidden case. While you make the stroke, nobody may shield you from wind or rain — it costs penalty strokes. Between strokes, on the other hand, the caddie may hold the umbrella without any problem. The rule of thumb is simple: during the stroke you stand alone in the weather.
Which aids are allowed on the course and which are not?
Almost everything between strokes is allowed: trolley, gloves, tee, umbrella, advice from the caddie and searching for the ball. It only becomes forbidden when a person or a thing physically stabilises you during the stroke or protects you from the elements. Devices such as rangefinders fall under the rules for artificial devices and are regulated separately.
What happens if someone kindly assists you during a stroke?
Then the forbidden support comes into being at that moment, even if it was meant kindly. If your playing partner holds an umbrella over your head in heavy rain while you play your approach, that is against the rules. The same applies if someone holds you steady on uneven ground so that you do not slip. Correct is: umbrella away or held by yourself, play the stroke, accept help again afterwards.