What's a spoiler?

Seeing how SWTOR relies heavily on story for its appeal, I think we can all agree that spoilers matter. Knowing how the big plot of your class story is going to end before you actually get to play through it certainly puts a damper on things, even if you have yet to discover the details of how it all plays out. Myself, I was accidentally spoiled for the ending of the Jedi knight storyline on another blog where the writer had casually mentioned at the start of the post that there would be "some spoilers", which didn't sound too bad to me, and then he ended up giving away the two biggest plot points of the class's storyline in two short sentences. Whoa! I still had lots of fun levelling up my Jedi, and there's still a certain appeal to wondering how exactly you're going to get to your final destination once you know what it is, but at the same time I do kind of wonder whether I would have felt differently about the whole knight plot had I not known in advance how it was going to end.

Yet every time I write a post about a class story, I struggle with how much of a spoiler warning I should give. I certainly don't want to ruin anyone's enjoyment of the story, but to be honest I also don't want people to shy away from reading my posts because they are afraid of massive spoilers that might not actually be there. The problem is, where do you draw the line?

I remember when the game had just come out, some people considered even things like revealing the name of your first companion a spoiler. It makes sense in a way, because I've certainly enjoyed the few times when an NPC ended up joining my character unexpectedly, as opposed to me having heard their name before and going "ah yes, this guy's going to be my future healer" as soon as I meet them in game. However, at the same time companion names are something that's incredibly hard to maintain secret, as spoiling yourself for that information can be as easy as clicking on someone else's companion on the fleet. Then again, there's certainly a continuum there as well - companions that are acquired early in the game or that serve as romantic interests naturally get a lot of exposure, but you can go quite a long time without ever finding out about companions that are unromanceable aliens and only join the player character very late into the game.

So, does that mean that talking about companions acquired in the latter half of the game is a spoiler and talking about the early ones isn't? There seems to be a certain expectation in fan circles that everyone must've played at least the first ten levels or so of every class and would thus know about any events and characters introduced there. Also, is it a spoiler to mention that a companion is romanceable?

And then what about story content outside of the class stories? The generic storylines are usually less engaging and thus also have less to lose by being spoiled in some way, but still... there are some surprises there that could potentially ruin someone's fun if they were revealed unexpectedly.

Where do you draw the line? What sort of spoilers do you shy away from and which ones do you not mind reading about?