*. Use as few tags as possible.
*. Limit yourself to a self-defined set of tags.
*. Tags within your set must not overlap.
*. By convention, tags are in plural.
*. Tags are lower-case.
*. Tags are single words.
*. Keep tags on a general level.
*. Omit tags that are obvious.
*. Use one tag language.
*. Explain your tags.