I've been listening to "Everyone" say what they think is the MLB slide rule. Some people get it and some do not so I went to the official rules at MLB.com and here is the REAL RULE.

(j) Sliding to Bases on Double Play Attempts If a runner does not engage in a bona fide slide, and initiates (or attempts to make) contact with the fielder for the purpose of breaking up a double play, he should be called for interference under this Rule 6.01. A “bona fide slide” for purposes of Rule 6.01 occurs when the runner: (1) begins his slide (i.e., makes contact with the ground) before reaching the base; (2) is able and attempts to reach the base with his hand or foot; (3) is able and attempts to remain on the base (except home plate) after completion of the slide; and (4) slides within reach of the base without changing his pathway for the purpose of initiating contact with a fielder. A runner who engages in a “bona fide slide” shall not be called for interference under this Rule 6.01, even in cases where the runner makes contact with the fielder as a consequence of a permissible In addition, interference shall not be called where a runner’s contact with the fielder was caused by the fielder being positioned in (or moving into) the runner’s legal pathway to the base. Notwithstanding the above, a slide shall not be a “bona fide slide” if a runner engages in a “roll block,” or intentionally initiates (or attempts to initiate) contact with the fielder by elevating and kicking his leg above the fielder’s knee or throwing his arm or his upper body. If the umpire determines that the runner violated this Rule 6.01(j), the umpire shall declare both the runner and batter-runner out. Note, however, that if the runner has already been put out then the runner on whom the defense was attempting to make a play shall be declared out.