Where [3][x][y] means "smoothly change the period of current sample by x*16+y after each tick in the division, never sliding beyond current period". The period-length in this channel's division is a parameter to this effect, and hence is not played. Sliding to a note is similar to effects [1] and [2], but the slide will not go beyond the given period, and the direction is implied by that period. If x and y are both 0, then the old slide will continue.
