First, about that enter key performing a "submit" in an edit box where I'm used to using it to divide my thoughts as I write: I've never found SO halfway as transparent as it ought to be. As a new user, controls for facilities I expected were simply not there, so I had the pleasure of thinking I was going blind for ten minutes. Nice use of ten minutes. Not just dimmed out, but not there. I'm extremely sympathetic to novices who find SO less than totally transparent. No dimmed control with a pop-up explaining "requires XXX reputation" like you'd expect on a site that actively engages disoriented newbies.
Just this morning I was thinking about "workflow equity". This includes all the habits of doing something in a certain way. Habits are a powerful asset, until the powers-that-be mindlessly yank them away. Such as using the enter key to divide my thoughts during the act of composition, even if it won't let me submit a multi-paragraph answer. Ubuntu did this with Unity. Google does this with how they format search results. SO does this with missing controls and enter keys that outrageously violate the principle of least surprise. And yes, these observations are relevant to this discussion. See Willpower: Rediscovering the Greatest Human Strength by Roy F. Baumeister and John Tierney or The Willpower Instinct by Kelly McGonigal about the importance of habit equity in conserving our surprisingly finite mental resourcefulness for more important matters.
Obviously, people with hardly any clue mainly search against the questions, not the answers, and it's hardly transparent that DUPLICATE is a transactional status meaning not that the item it marks is itself duplicate (as a question), but that any answers added would be because answers are already EXTANT, which is what duplicate really means here.
So what recourse?
Ask the question this way (if it hasn't been already): What technical terms do I need to know to effectively search SO for items pertaining to strange syntax or grammar in the C language?
I can think of a few: digraphs, trigraphs, operators and punctuators (esp. ternary operator), anonymous members, the C pre-processor.
With more questions directly concerning lexicon, we might have less ungraspage all around. The duplicated confusion can be directed to the meta-question about appropriate lexicon, while the (not yet) duplicated effort of repeating extant answers can be directed to the extant answers.
Heaven forbid SO takes asking the question as a first order activity, with a distinct and appropriate mechanism of its own for averting duplication of effort.
The first flags that came to me were crib, primer (from the movie Contact), Linear B, and Rosetta stone. Then I thought stone in shoe, snag, pitfall, trap for the unwary, quicksand. I like quicksand the best. An example of quicksand in the R language is the "promise" mechanism of lazy argument evaluation. It's not just a simple identification of a creepy-crawly with a certain number of wings and legs (like the :> digraph). There could be any number of ten line code fragments posted under WTF? They would all relate to the same quicksand. In C you have the disappearance of automatic storage after you pass it into a routine that hasn't finished with it yet, even though the function call returned long ago. node.js has some weird business that can bite you, and so does mongodb. For embedded programmers, ground loops with serial ports can make you think you're losing your mind.
The problem with quicksand is that it's generally invisible until you've stepped into it, even if you thought you knew. Herzog's Encounters at the End of the World has a brilliant sequence where everyone wears buckets to simulate a white-out while trying to extend and follow a rope to safety. It's harder than it looks the first time you try it. The point of that exercise is not to mark their effort as "duplicate no need to bother with the rope exercise, someone else already found the safety shed" but to provide some necessary orientation so that next time they can find the shed themselves. A quicksand or swamp flag could a starting point for finding things you need to know when you don't yet know how to ask the question.