The rules-as-written tag is used by people to mean three disjoint things:
- "I know this is crazy, don't tell me that; I want a legalistic loophole type exploit of the rules" (for example, What methods exist to get infinite or extremely high caster level?) or
- "I kinda don't want anyone's opinion; I want what the rules say" (for example, RAW, can you use the Sharpshooter and Great Weapon Master feats to make an improvised weapon attack with a longbow?, what we have Good Subjective, Bad Subjective for), or
- "This is a question about the rules" (for example, Does Arcane Eye transmit information if the caster moves to a different plane?, which it's not necessary for).
At Stack Overflow where I'm the most active at, this is grounds for deleting the tag because it's ambiguous and disambiguating it i.e. replacing it with more specific tags in questions if any are needed.
- The 1st item falls under something like rule-abuse (judging by the comments, a separate discussion is in order on what kinds of rule-lawyering questions are on topic and what the exact tag name(s) should be).
- The 2nd item could use something like just-rules. But I doubt that such a question formulation is on topic because in pen-and-pencil RPGs, a constructive interpretation is an integral part of the rules. Because, you know, words' meanings are intrinsically imprecise and unlike e.g. CRPGs, there is no hard-and-fast reference implementation to check unclear cases against. In this case, it's the same as the next item.
- The 3rd item, as the OP said, does not warrant any tag at all because it's the primary topic of the entire site. It's implied by default from the sheer fact that the question has been asked on this site.