Prohibition in Japanese depending on level of formality I have learnt two variants for prohibition: - - depending on the level of formality… But does an intermediate form of - or - exist as well?

Yes, all combinations are possible. Taking as an example, you can say all of the following (roughly in the descending order of formality):

*
*
*
*
* (())



may look like a weird combination of a colloquial word and the polite form, but it can happen when a teacher say "don't ..." to their students, for example.