The R&A have revised their position on the use of stabilising rings. As of 03/05/24, any scores returned for handicap purposes when the stabilising rings are in place are acceptable for handicap purposes.
The definition of ‘hole’ in the Rules of Golf states that if a lining is used, its outer diameter must not exceed 4.25 inches. The lining must be sunk at least one inch below the putting green surface.
The R&A recommend that the one-inch stipulation be followed as far as possible, as having the liner higher can result in other issues. For example, there is an increased risk of:
• The ball bouncing out of the hole; or
• The liner/stabiliser protruding above the ground; or
• The earthen wall moving away from the liner/stabiliser leaving the liner/stabiliser exposed or protruding, so further increasing the risk of bounce-outs.
Further details can be found from the Adverse/Extreme Weather Reference Guide.