I don't understand how to make the 'case' feature work.
Adobe defines it as follows:
Shifts various punctuation marks up to the position that works better with all-capital sequences or sets of lining figures.
Now, in the fonts that I have considered it is always a simple Single Substitution of 'case' type.
Let's assume a classic use: in Spanish, in front of a capital letter. I want to replace the questiondown with one appropriately raised, so that it rests on the baseline:
how does a simple 'case' know if after question there is an upper or lower case, that is how is it case-sensitive?
Evidently something escapes me, if I only see a simple Single Substitution and not, for example, a new contextual chain replacement ...