Help understanding the "Cat Line" column formula in the Foundations Template

I am trying to understand the formula in the “Cat Line” column of the Yearly Budget tab within the Foundations Template. Specifically, my question is why the formula in this column checks if the Type = “Income”. It is not clear to me why this is relevant, but when trying to replicate with a new sample list, I cannot make it work.

Full disclosure, this is out of pure curiosity on how to dynamically create a list that is grouped/categorized. If Tiller is not interested in explaining their formula, that is okay - just let me know.

Edit: I am asking about the formula for Excel. In the Foundations Template it is column AT (hidden by default).

Thanks.

Maybe you are referring to a small amount of redundancy in the formula here…?

It looks like the main effect of the test for “Income” is to add the two extra rows required when transitioning from the Income to Expense type header.

(These layout formulas can be pretty fussy. I just implemented some for the new Insights replacement template and there is a lot of trial and error required to get them to work right.)

Randy - Thank you for the reply. That makes sense and is helpful for me to understand.