1. Use as few tags as possible.
2. Limit yourself to a self-defined set of tags.
3. Tags within your set must not overlap.
4. By convention, tags are in plural.
5. Tags are lower-case.
6. Tags are single words.
7. Keep tags on a general level.
8. Omit tags that are obvious.

https://karl-voit.at/2022/01/29/How-to-Use-Tags/