12.17.2.2 The base runner may not interfere with a fielder attempting to throw the ball.
No reference to sliding or not sliding, in or out of base path. Also, no mention of intent or contact required
Also:
12.17.2.4 The base runner who immediately precedes the batter-runner and who is not yet out may not intentionally interfere, in the umpire’s judgment, with a fielder who is attempting to catch a thrown ball or to throw a ball in an attempt to complete a play.
EFFECT—The ball is dead, the batter-runner and base runner are out, and each other runner must return to the last base legally touched at the time of the interference.
Also this:
12.17.3.1 An offensive player, who no longer has status (a retired runner or a runner who has scored), may not interfere with a defensive player making a play on an active runner.
EFFECT—(12.17.3.1 and 12.17.3.2)—The ball is dead, and the runner closest to home plate at the time of the interference shall be declared out. Each base runner must return to the last base legally touched at the time of the interference, unless forced to advance.
Short answer: no slide required, but if you do slide and choose to pop up you had better make sure you don't interfere
No reference to sliding or not sliding, in or out of base path. Also, no mention of intent or contact required
Also:
12.17.2.4 The base runner who immediately precedes the batter-runner and who is not yet out may not intentionally interfere, in the umpire’s judgment, with a fielder who is attempting to catch a thrown ball or to throw a ball in an attempt to complete a play.
EFFECT—The ball is dead, the batter-runner and base runner are out, and each other runner must return to the last base legally touched at the time of the interference.
Also this:
12.17.3.1 An offensive player, who no longer has status (a retired runner or a runner who has scored), may not interfere with a defensive player making a play on an active runner.
EFFECT—(12.17.3.1 and 12.17.3.2)—The ball is dead, and the runner closest to home plate at the time of the interference shall be declared out. Each base runner must return to the last base legally touched at the time of the interference, unless forced to advance.
Short answer: no slide required, but if you do slide and choose to pop up you had better make sure you don't interfere