I have a trigger warning policy in my syllabus. it’s been there for a few semesters. it encourages (w/o mandating) students to use trigger warnings themselves, explains why it’s considerate to do so, and states that I, as the instructor, will tell students in advance about intense subject matter.
because it’s just more my style, I tend to be pretty casual with my “warnings.” I usually don’t even call it a trigger warning. I’ll just describe the subject matter of upcoming readings. for example, the students in my Rhetoric of Confession class have a group project where they pick from a list of memoirs to read parts of and present on, and I give them a list of keywords for each book which alerts them to potential triggers while also just giving students a taste of what each book is about.
the main thing I have to say about this is it just really isn’t a big deal in my class. no one has “used” being triggered to “get out” of anything. if anything, I think just letting students know that I understand that our course content can be triggering and/or uncomfortable and that I would be responsive if they were triggered and/or uncomfortable makes many of them feel safer and/or more comfortable.
I believe, from my experience as a TA & instructor, that students in courses without any kind of trigger or content warning are probably more likely to check out & not do work & skip class for reasons of trigger / trauma / discomfort / anxiety than are students in courses where they feel like those concerns & responses will be taken seriously.