Getting the bike ready for the season and I bled the front calipers without a problem. Then I began to do the rear caliper but couldn't easily loosen the rear bleed screw. ( I know, 'righty tighty - lefty loosey'.) I've never run in to a bleed screw with 'reverse' thread on it before but, before I snap it off, I thought that I'd ask what, perhaps, might be the dumbest question of the day:
Could it be a reverse thread, or should I simply pull harder on it?
It's definitely righty tighty/lefty loosey so you were going the correct direction.
Just be careful using more torque as those bleed screws are hollow & do twist off pretty easy.
Try a bit of heat on it first, then if still no go try tapping on the top of the bleed screw with a hammer as you try opening it with the wrench on it. (this will probably trash the screw top but in a lot of cases that is the only way).
Just remember it is much easier to work on it & remove if you DON'T twist it off so stop short of applying so much force you twist it off.