I presently attend SpecEd. I'm allowed to leave the classroom at once if I'm afraid of the teacher (I'm scared of angry people, especially in positions of authority). I'm allowed to stay in the classroom during breaks because hypervigilance makes it difficult for me to be with a few hundred people in the break room. I'm allowed to take breaks and read or walk a little when I need to. Also, I might get alternate assignments for Art (drawing) class but that hasn't been decided yet. The reason is performance anxiety.
I also don't have to do my homework if I have a good reason, but that goes for everyone.

Back when I was physically ill and attending regular high school, I got extra time for tests because of pain and performance anxiety. I was also allowed to skip whatever classes I wanted (needed) to. Also, if I were to fall asleep during class, every single teacher would let me sleep - but that wasn't anything official. Just compassionate teachers.
Oh, and no one minded if I did my homework or not. Given that I was attending 11 therapies and hospital visits a week, everyone understood I simply didn't have the time.

I'm sure there are more things, but this is all I can come up with right now.