Ahaa, but here it is you are mistaken, or rather, the how/why is the important detail.
the term as it is currently used, especially in games, makes us quickly realize what type of content is being referred to
Why do people know what it means? Because they have previous knowledge of how other people use it and about the context they see the term used, or because they understand the meaning, from the spelled out situation the letters describe?
I dare day, they can't understand the meaning from the words, because it is an abreviation. They do not know the words to begin their understanding. It is like lol. People see other people use it and grasp the meaning from context. Or because someone taught them. Insert Lot's of Love joke here ;-)
It get's worse, if you look for translations. It is internet slang. People just use the same letters, like said lol.
It has no meaning outside of the internet context. Not that I would be aware of. Was reading a Playboy magazine being called "nsfw" back in the day? It probably was inapropriate, but times can be deceiving, as it apparantly once was not considered sexual harrasment, if one would slap the behind of a female coworker.
If I try to take a step back and imagine a person not knowing the internet. And then I would present to the person a term "not safe for work" as an attribute for a thing. What would that person think it means? A faulty piece of equipment? Harzardous goods? Sub par materials suitable for private use, but not safe for work?
While searching for this, it might also have started as not suitable for work, but with abreviations one can never be sure. People being lazy might have prefered a shorter version with safe instead of suitable. The usually pedantic and thourough people at the wikipedia have nothing to say about the etymology, other than it being internet slang and it being used for links, so you know before you click.
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I do not know where you got the dodge shooter meaning for rogue like. That term has been debated since it's beginning with hardcore fans insisting on some meaning in a literal sense, like you described: being a clone of that rogue game. To my understanding there are two elements to being rogue like nowadays. A random "run". And some sort of permadeath of a customizeable character. If your runs get easier the more you achieved, people even call it rogue lite.
But as you said in a way. Words mean what we make them mean. Even if we use them "wrong". For some euphemisms there even is a cycle, as the euphemism starts getting as offensive as the original word it substituted. Who would have guessed (<- sarcasm).