Obstruction
Obstruction by third baseman dropping a knee and impeding the runner
Obstruction by first baseman blocking the base before possessing the ball and impeding runner
Obstruction by catcher without ball causing runner to alter their path to the base
Interference
Interference by Retired Runner (runner forced to second interferes with the subsequent play)
Interference by the batter repositioning in the batter's box
Batter interferes with catcher's attempt to make a play on another runner
Interference with first baseman attempting to make the initial play on a batted ball-also Malicious