There has been agreat deal of confusion in this thread (no pun intended
).
The issue about 'Coarse' ot 'Fine' pitch is totally irrelevant - the real subject is the shape of the ScrewDRIVER - or, even more precisly, the RECESS in the screw head.
Of course the physical or nominal size of the thread has a bearing upon which size designation screwdriver is needed to fit or remove the screw but 'twas ever thus, whether talking about ISO, Unified, Whitworth . . . or whatever . . . The thread 'Standard' in use does not concern itself with the size or shape of the driving recess so you could have a 'Standard' M2 screw with 0.4mm pitch or 0.25mm pitch (Coarse and Fine series) with a Slot, JIS, Torx, Philips, PoziDriv, SupaDriv or any other recess (though I doubt that the last two referenced would be aplicable to an M2 Screw!) just as you could have a Countersunk, Raised-Countersunk, Cheese, Hex, Button, Cap. . . . or any other 'head'.