Fyldewhite
Tour Winner
It's rule 8 for me too. Perhaps the wording didn't envisage a player would ever deliberately damage the course for this purpose??
I read as breaking 8.2 indicating line of play,
you can mark the line of play, but it must be removed before a stroke is made.
Pretty hard if its a gouge in the ground, but nothing stopping you from using something already there.
8-2 - Indicating Line of Play
a. Other Than on Putting Green
Except on the putting green, a player may have the line of play indicated to him by anyone, but no one may be positioned by the player on or close to the line or an extension of the line beyond the hole while the stroke is being made. Any mark placed by the player or with his knowledge to indicate the line must be removed before the stroke is made.
Exception: Flagstick attended or held up – see Rule 17-1.
b. On the Putting Green
When the player’s ball is on the putting green, the player, his partner or either of their caddies may, before but not during the stroke, point out a line for putting, but in so doing the putting green must not be touched. A mark must not be placed anywhere to indicate a line for putting.
PENALTY FOR BREACH OF RULE
Match play – Loss of hole; Stroke play – Two strokes.