Whether a note remains useful rarely depends on how complete it is. What matters is whether your future self can quickly understand why it exists.
Instead of adding more categories, I focus on three things: the original question, the conclusion, and the limits within which that conclusion applies.
Leave a path back to the conclusion
An answer without context becomes difficult to trust after a few months. A little background, the alternatives you tried, and the sources you used make a note verifiable again.
- Let the title describe the problem directly
- Explain the situation at the beginning
- Record the next step or limitation at the end
Organize less and revisit more
Notes become valuable when they are revisited. Instead of spending too much time designing a perfect filing system, reopen old notes, combine repeated ideas, correct outdated information, and turn the mature parts into articles.