To point out a certain behaviour is not allowed, you can use the Korean grammar pattern -(으)면 안 되다. Luckily, it is a rather easy to understand pattern.
The most common imperative in Korean is the form -(으)세요. You use it to place orders, to make requests, give directions, etc. So it is important to know.
To ask for or to give permission, you can use the Korean pattern -아/어도 되다. It is a simple way to do all the things you do with the English word “may”.
Expressing that something is required or necessary can be done easily by using either -아/어야 해요 or -아/어야 되요. Though complicated-looking, it is easy to use.
-지 마세요 is the negative of -(으)세요. It is the Korean imperative to demand or request someone to not do something. It is important to know as it is common.