When playing a round of golf, a golfer tees it up on 18 different tee boxes. The tee boxes are not the same size. Some are wide. Some are narrow. Some are on perfectly flat ground, and others are not the best.
When a golfer encounters a bad tee box -- whether it's too narrow, or points the golfer at water or trees, or they have it on poor ground -- they might be inclined to think they can move the tee markers to make the box bigger or point them in a better direction. Is that legal under the Rules of Golf?
Can a golfer move a tee marker to change the tee box?
Under the Rules of Golf, a golfer cannot move the tee markers for any reason. Once they're set for the competition in question, they need to remain the same for everyone. A golfer cannot move them, as they indicate the teeing ground area. They're set for a reason.
However, a golfer doesn't have to stand between the tee markers when they hit their tee shot. The only thing a golfer has to do is hit their tee shot in the area that counts as the tee box.
Of course, if you're playing in a casual round, then go for it. Just try to put them back to where they were when you're done teeing off on that hole.
Can a golfer move a tee marker if it's in the way of your shot?
After your tee shot, though, you're able to move a tee marker if it interferes with your next shot. If you've duffed a tee shot, and it winds up near the tee marker in front of your ball, then you can move it. The same wound be true if your shot winds up on the tee box of a different hole than the one you're playing. In those situations, the tee markers are just temporary objects that can be moved.