Okay, so, right, okay. Um. In German schools (and probably some other countries...?), many many years ago (possibly still today? or maybe it's all digital now? what am I saying, this is German schools), the blackboard in every classroom was a large, green, rectangular middle part and two square "wings", one on each side (as wings are wont to be...). They can swing in and out, providing extra room for writing on the outer side of the wings. Also for extracurricular shenanigans such as writing "[name] + [name] = SEX" in the middle, swinging the wings closed to hide the writing and then breaking out into hysterics when the teacher opens the blackboard to reveal your incredibly highbrow joke.

This type of blackboard is quintessential to my recollections about and concept of school.

Why am I going into such unnecessary detail about this? I have ADHD and possibly autism, I need you to understand what I'm saying and I can't find any sources of this existing in the English speaking world and I can't find an English word for those "wings" either. I can barely find a German one ("Tafelflügel"? I don't think it's ever come up before in my life).

So here's a picture:

The width/height of the "wings" and the height of the middle part, that's a metre. Thank you for coming to my TED talk.