While the most obvious True Name to protect is a student's own, it's worth thinking about how they must be careful with others' as well. Students telling tales about their old high school friends would be best off using false names there as well, lest those same friends decide to pay campus a visit. Students who knew each other before attending Elsewhere U likely know one another's True Names, but any abuse of this power is moderated by the knowledge that the other could well retaliate in kind.
Oh god though imagine your high school friend visiting - “No, no, Greg, listen, I’m dead serious, you’ve got to call me Hashtag literally the entire time, I’m not joking at all, no I can’t explain why - look, I thought it was funny, okay? Please just do this for me. Also pick a nickname, it’s literally life or death, hahaha what a funny joke i just made but really what’s your nickname, you cannot visit me otherwise.”