Under the current Rules of Golf (16.1c), only limited repair of damage to the putting green is allowed – for example, a player may repair any old hole plug or ball-mark on the green on their line of play, but a player must not repair any other damage on the green - such as spike marks - if it might improve the line of their putt.
However, under the proposed changes (13.1c(2)), “damage on the putting green” will be defined to include all types of damage such as ball-marks, shoe damage and animal damage. The player will only be allowed to repair damage with their hand, foot, ball-mark repair tool or a club, and must not unreasonably delay play.
The reasons for this change stem from the frequent questions among players and referees about whether a particular area of damage on the green is a ball-mark that may be repaired or is a shoe mark or other damage that shouldn’t be touched. A sensible addition in our opinion.