I would like to say, while I'm generally not too sure how I feel about trigger warnings, that when I had my abortion in college and went around telling my professors what was going on, one English professor proactively looked at the syllabus, told me the next class was going to be about Death and that maybe I would want to miss it. I would have gone and I wouldn't have been triggered by the lecture, but I really needed time, space, peace, and to be with myself at the time. I was so, so greatful he did that for me. To me I guess that is the way a trigger should be dealt with. A student who maybe can't handle something should get a private, considerate "heads up" from the teacher, and the student can then choose to participate or not. If I had triggers I would not want the entire class to know about them, I think it would make it worse.
Of course, this is the goal. It's not necessary that everyone knows who or what is being referred to, but a simple layout of a syllabus would qualify as a trigger warning. It's merely having the availability of information that will be presented in a class, or an article, or a forum, or what have you. People seem to get extremely bent out of shape over... providing what may be encountered, and I honestly can't understand how people equate it with censorship. The topic is still present, the content still there, there's merely a warning going into it. It's not different than network television providing a content warning before graphic imagery. And if you want to get to lower levels even, wherein we're discussing people that have certain phobias or would just rather not see something on, say, their tumblr dash or hubski feed, and you're providing content you know someone will see and would rather not, providing something as simple as a tag saying "spiders" puts you out none and provides a benefit for someone. Of course this isn't such a large matter if you forget as it would be if we're talking about potential trauma. I see plenty of people complain about triggers existing and being shamed for not including them, but I've yet to actually see someone call out another for not including triggers unless it was a serious matter. Mostly everyone complaining about having to provide a content warning is completely oblivious to the effects of trauma.