Can anyone cite the actual rule against manufacturers stamping a directional aid or mark on the golf balls they produce? I took a quick look at the rules and could find no mention of this.
There is no rule, the manufacturer can place a cheater line on the ball...see USGA decisions. There is some debate (stupid debate of you ask me
), that the golfer can't place a cheater line on the ball, but the manufacturer can. I never bothered to look into that bit of insanity for obvious reasons.
Bottom line, so far as I can make out, for 90 years the rule was quite obvious, the green cannot be marked to indicate the line of a putt.
R&A 1899 rules
20. "When the ball is on the putting-green, no mark shall be placed, nor line drawn as a guide. The line of the putt may be pointed out by the players caddie, his partner, or his partner’s caddie, but the person doing so must not touch the ground."
This rule makes no mention of marking a ball prior to play. Who marks their ball with a line once it is on the green? I also believe that by the context of the rule that it is the putting surface which is in question...not the ball. For some wild reason, the USGA didn't continue using that sort of language from 1988 and instead used
"Any mark placed during the play of a hole by the player or with his knowledge to indicate the line shall be removed before the stroke is played."
There is no question the context of the putting surface is not included...I think by mistake because the decisions do not uphold this wording of the rule.
Ciao