What holes are played on a diatonic harp with notation “+6#3”?

Question

I found a blues riff tab that goes like this:

-2 -3b +4 -4b  +6#3     -4b -3 -2

What does it mean to blow on the sixth hole and block the third? Does that mean you are blowing in 4, 5, and 6? Why not just write +456?

Answer 1

+6#3 means to blow out through holes 6 and 3, and only holes 6 and 3, which form an octave. The # means to use your tongue to block holes 4 and 5.