England Golf state the following:
Mats (tees and fairway mats)
Acceptable Scores may be returned in Competitions and in General Play when there is a Local Rule in place requiring the compulsory use of fairway mats to protect the natural surfaces of the course, during the preferred lies period.
Suggested wording for local rule - ‘When a player’s ball lies in a part of the general area cut to fairway height or less and a putter is not being used for the stroke, the ball must be lifted, placed on and played from an Astroturf, or similar type, of mat. The mat must be placed as near as possible to where the ball originally lay, and the ball must be placed on the mat. The ball may be cleaned when lifted.’
Bunkers
Providing a Local Rule is in place, bunkers may be taken out of play and marked as GUR for situations such as severe or prolonged wet weather. Bunkers flooded with water, can be marked as GUR; allowing scores to still be acceptable and returned for handicap purposes. Players must be made aware of which bunkers are GUR before play. There is no limit on the number of bunkers that can be taken ‘out of play’.
Temporary Greens
For scores to be acceptable, no more than 2 temporary greens are allowed to be used. For a 9-hole course, only one temporary green will be allowed. Whilst temporary or alternative greens are acceptable for handicapping purposes, whenever the length of the course length has been increased or decreased by more than 100 yards for an 18-hole round or 50 yards for a 9-hole round, the adjustments to the Course Rating and Slope Rating set out in Appendix G of the Rules of Handicapping must be applied.