I would question whether double and buzz belong with:

full stroke
down stroke
up stroke
tap stroke

To me, a double and buzz is types of bounces; unfortunately, they get the term stroke, but are very different than the full, down, up and tap strokes.

I can play a double in many different ways; all full strokes, all taps, down/up or up/down ... depending if any one of the notes are to be accented.

So all I'm saying ... they are in a different catagory ... and would just go under the title of Rudiments.

All the rudiments can be played using the four basic strokes; full, down, up, tap.  The word "stroke" to me means what the wrist does. If you let the stick bounce, you more than likely played a DOWN or TAP stroke in order to get the stick to the surface, then leaving it there to bounce freely or controlled (stopping with your fingers or lifting of the stick).

What do you think?