The experience of each season in regard to the conflicting opinions of umpires and players in their interpretation of the code of playing rules, has made it a necessity on the part of the editor of the GUIDE, to devote a special chapter each year to the subject of properly interpreting every important rule of the game. This year we make up this special chapter in the form of an _Explanatory Appendix_ to the new code, which is officially indorsed by the President of the National League, and the Secretary of the Joint Committee on Rules of the League and the American Association. Taking up the rules of the new code in their regular order we proceed to give the official interpretation of the practical application of each newly amended rule, as also of every rule, of the correct definition of which there is likely to arise any question. THE PLAYERS ON EACH SIDE. "In no case shall less than nine men be allowed to play on each side." So says Rule 14. The practical application of the rule is that if a club has not nine men ready to take the field at the hour appointed for beginning a regularly scheduled championship-game, the club short handed must forfeit the game. Moreover, if they begin play with the required complement of men, and one of the number becomes injured and disabled from service in the field, and they have no legal substitute player to take the disabled man's place, the game cannot be continued with but eight men in the field, and therefore it must be similarly forfeited. PLAYERS MUST BE IN UNIFORM. Rule 17 requires that "every club shall be required to adopt uniforms for the players;" and Rule 28 renders it necessary that at least one substitute player shall be ready "in uniform" to take the place of a disabled player, or to become the tenth player of the team in accordance with section 2 of Rule 28. A TENTH MAN AS SUBSTITUTE. Besides the regular substitute player required to be ready to take the place of a disabled player, Rule 28--a new amendment--admits of an _independent substitute player_ on each side, whose services in the field are held subject to the requirement of either of the two Captains whenever he shall deem it advisable to remove any player, who, though not disabled "by illness or injury," is not doing the work in the field to the Captain's satisfaction. But such substitute can only replace another player at the close of a regular innings play; and, moreover, the player whose place the extra substitute takes, cannot again take part in the game then being played.