Shoulder length or above can be worn down.

If you cant put it up all the way but still want it out of your face a half up half down would work well. Thats what i used to do when my hair was borderline too long to wear down but not long enough to be a ponytail

When mine was that short I used to pull the top part up out of my face since I couldn't get all of it into a tie. I also just like to keep as much of my hair secured as possible so it doesn't get into anyone's food or drink tbh.

My hair is pretty short (I can’t put it into a bun/ponytail) and I’ve never been spoken too about having it half-up-half-down. I’d suggest that instead of leaving it fully down just in case :)

When my hair was shorter and I couldn’t put it all the way up, I would wear beanies a lot. Or just pull the top part up.