Knowing a file type is an "esoteric technical requirement" ?
Yes, this comment is for real. I'm the head of IT for a university and we do online applications. We actually accept everything within a given size requirement (which people are unable to respect). I have a bunch of scripts that run over all applications in the end to put them in the right formats, to do OCR for the photos of a printed PDF form that has been filled out by hand in pencil, I even run a script to scrape annotations in PDF portfolios to scrape video links and pass them to youtube-dl, to ensure everything submitted gets picked up and is provided for evaluation.
This is why I think it would be nice if there was at least some responsibility on the part of the student.