Flagstick: Defining It and Its Role in Golf

Royal Liverpool Golf Club
A flagstick at Royal Liverpool. Photo courtesy of Where2Golf.com; used with permission

A flagstick is exactly that: a stick with a flag on it. You see them on putting greens to mark the location of the hole. Some courses color code the flags on flagsticks to denote if the hole location is near the front, center or back of the green. Another way of doing the same thing is to put the flag high, middle or low on the stick. (A course that does this should note the practice on its scorecard or pin sheet.)

It is a penalty for the ball to enter the cup with the flagstick still in the hole if the stroke taken was played from the surface of the putting green.

In the golf rules, situations involving the flagstick are covered in Rule 17 - for example, when the flag should be removed, what happens when a golfer removes the flag without authorization, what to do if the ball hits the flagstick or lodges against it, etc. See Rule 17 for rulings on those and other flagstick-related scenarios.

Definition from The Rules of Golf
The official definition of flagstick from the Rules of Golf includes some information about the specific shape of the flagstick. Here is that definition, from the USGA/R&A:

The "flagstick" is a movable straight indicator, with or without bunting or other material attached, centered in the hole to show its position. It must be circular in cross-section. Padding or shock absorbent material that might unduly influence the movement of the ball is prohibited.

More reading about flagsticks:

Also Known As: Pin, or sometimes shortened to just "flag"

Alternate Spellings: Flag stick