What do the bins mean in Severance?

In the TV series Severance, those in the macrodata refinement department excise numbers from a file based on what emotion it provokes. There are 4 emotion categories, and there are 5 bins available, each of which stores any of the 4 categories.

You can see here each bin stores any of the 4 emotion categories (WO, FC, DR, MA). It looks like a bin at 100% capacity will have some distribution of these emotions, i.e. not every emotion category has to be filled to 100% for the bin to be 100% full. It is explained in the employee handbook (which is on Apple Books) that you can get it wrong and put data in the wrong bin.

It is explained in the TV series that the numbers provoke an emotion allowing you to categorise them, but is there an explanation as to what each bin means, i.e. how do you know which bin to put it in?

I am a mathematician IRL so naturally, I'm trying to figure out what this whole process means, hopefully ahead of season 2. I think it would be beyond the scope to theorise in answers - I am looking for any clues viewers have picked up on that address this question.

• Are you sure WO, FC, etc are the emotion categories? I thought the numbers bins were--from the ep: "Each category of numbers presents in such an order as to elicit an emotional response in the refiner. Cat 1 numbers, for example, feel a certain way on sight. They'll be sort of disconcerting, scary." Jun 21 at 14:42
• @Kitkat Yes, page 6 of the handbook (which is part of the Lexington Letter on Apple Books) says there are 4 emotion categories. WO = melancholy, FC = joy, DR = fear, MA = rage. Jun 21 at 14:54