I allways thought all quests are "side" ... Except for "get rid of tadpole" ... with that oddity, that even different ways to try that, are basicaly side quests.
I dunno, to me journal seems fine. :-/
There are different types of “side” quests but most RPGs will categorize your missions. Such as main mission, story missions, non-story side quests. If you have companions, sometimes you’ll get companion quests.