With respect to the equipment which may be used to play the game, The Rules of Golf (“the Rules”) reference the Equipment Rules. In general, the Equipment Rules are “descriptive” and “restrictive” in nature – defining what golf equipment should look like and limiting how it performs.The main objective of the Equipment Rules is to ensure that technological advances in the design and manufacture of golf equipment are in the best interests of the game of golf. While not wishing to stifle innovation, the purpose of the Equipment Rules is to protect the traditions of the game, to prevent an over-reliance on technological advances rather than on practice and skill, and to preserve skill differentials throughout the game.It is the role of The R&A’s and USGA’s Equipment Standards Committees to interpret and apply the Equipment Rules relevant to clubs, balls, devices and other equipment and to determine and advise which equipment conforms and which equipment does not. The Committee is also responsible for recommending modifications to the Equipment Rules, if and when changes are believed to be necessary.In order to achieve consistency in the decision-making process, a database of all previous decisions is kept and maintained. Also, over time, the Committee has developed a comprehensive set of “guidelines” based on these decisions to help interpret the Equipment Rules in a consistent way.The Equipment Rules incorporate many of these guidelines and interpretations to help equipment manufacturers and designers, tournament officials, players and other interested parties interpret and apply them. The purpose of Supplementary Paper A is to offer advice on the procedure an official should follow when faced with an equipment ruling immediately before or during a competition.Many of the Rules relating to clubs, balls, devices and other equipment can be technical and complex in nature. However, almost without exception, the Equipment Rules become understandable after only a brief explanation, or with the aid of a simple diagram. Whenever possible, the Equipment Rules will attempt to explain both the background to a provision and the objective behind it. Also, where practical, the Equipment Rules will offer advice as to how best to carry out certain measurements.Throughout The Equipment Rules there are specific sections which are highlighted by blue text. These sections are either direct statements of Rule 4 or contain specific requirements for equipment. These are the most important sections of The Equipment Rules and together constitute the specifications against which equipment is evaluated.