кяαzєя proposed the original version of the following policy in this answer. This is an edited version of that proposal.
Since we are an English-language site, we should set up a precedent from now on about tagging:
If the title has an official English localized name, use that. (That means: Use the official English name, where available, rather than the Japanese name.) Both should be synonyms.
- If there is no official English name, use the Japanese romanized name until such a time that there is. Once there is an official English name, then merge the existing tag into the English name (i.e. replacing it as the main tag), leaving the Japanese name as a synonym of it. Update the tag excerpt and wiki to reflect as needed.
If the full title exceeds the character limit (currently 35 characters), then:
Use the official (or widely fan-accepted; use search results as a benchmark for this) abbreviated Japanese name or abbreviated English name (if applicable), e.g. Oreimo.
If there is no abbreviated name (official or otherwise), use up to the first 5 words (plus or minus 2, so the title doesn't feel cut off). For instance, in the case of the series My Status as an Assassin Obviously Exceeds the Hero's, the tag could be either ansatsusha-de-aru or my-status-as-an-assassin. The ideal acceptance criteria would be that it is distinguishable by it as a partial title.
Both would be synonyms of one another, with the English name as the main tag (where applicable).
If there ever is an official abbreviated name (or widely accepted name within fan circles, using search results as a benchmark), the tag name can be changed accordingly.
The tag wiki should be updated to reflect abbreviations as needed.
If there is uncertainty or confusion regarding what name should be used for a specific series tag (e.g. very generic names), we can handle such edge cases on a case-by-case basis here on meta.
This should cover around 75% of cases involving series-related tagging.