Basically for a writing sample, as I understand it, but, as noted, there are subject specific AP tests (many of which are a grind even for AP students, though APUSH is notoriously easy, or was in my day) as well as subject specific ACTs (I believe the subject specific SATs, which are fairly new, are a response to the ACTs long standing practice of having both generalized and subject tests. ) Back in the day, (which sounds like it was also your day, or close to it) some colleges within universities would require particular ACT scores on particular tests for admission, I believe. Some universities even refused to accept the SAT, in favor of the ACT, because the SAT was generalized, but I never understood that since I understood it to always be the generalized ACT they referenced.