Yeah this is a somewhat bad guide at least as far as some of these entries
I would also add:
ad hoc = sort of made up for this one situation; "ad hoc attendance system" means they're not following the structure; carries an implication that it's more or less working but maybe not the best way
de facto = it doesn't have the designation but regardless of that, the meaning of the designation is what's happening; "de facto manager" means they don't have the manager title but that's the job they are doing
per se = I'm being nitpicky about details so please be careful not to read anything into my statements other than what's specifically said; "he didn't drive off the road per se, but he skidded on the turn and he was way out of his lane"