PASS will Pass through the notes in the range selected - meaning here everything below 65 is blocked -
EXCLUDE is the opposite - everything in the range selected is blocked (excluded) -
FREE - you can select certain notes to block - just click a key and it turns red (BLOCKED) SHIFT+CLICK will select al the same notes to block - COMMAND+CLICK will block and octave - COMMAND+SHIFT+CLICK will block ALL keys