United States Golf Association
Golf’s governing bodies have made available a Model Local Rule (MLR) to further limit the use of Green-Reading Materials.
MLR G-11 enables a committee to limit players to using only the yardage book that it has approved for use in the competition.
This local rule is intended only for the highest levels of competitive golf and, even then, only for competitions where it is realistic for the committee to undertake an approval process for yardage books. It will be available starting January 1, 2022.
The local rule gives a committee the ability to establish an officially approved yardage book for a competition so that the diagrams of putting greens show only minimal detail (such as significant slopes, tiers or false edges that indicate sections of greens). In addition, the local rule limits the handwritten notes that players and caddies are allowed to add to the approved yardage book.
The purpose behind the local rule is to ensure that players and caddies use only their eyes and feel to help them read the line of play on the putting green.
The USGA and The R&A developed MLR G-11 in response to feedback from several professional tours.
The MLR, along with question-and-answer guidance, can be found here.
As the local rule should only be adopted at the highest levels of competitive golf, all other golfers will continue to be able to use green-reading tools so long as they meet the requirements established in 2019. For more information on the current rule, see usga.org/grm.