How should we romanize English words that have been borrowed into Japanese?

Question

For example, the Japanese title of the 2013 Spring anime that has AHSMBs in it is 銀河機攻隊マジェスティックプリンス. When giving a romanization (as opposed to a translation, which would be "Galactic Armored Fleet Majestic Prince" or something), should we romanize it as "ginga kikoutai majesutikku purinsu" or "ginga kikoutai majestic prince"? In my experience, the latter style is overwhelmingly favored among English-speaking anime communities on the internet.

I'm asking because I noticed that the toaru-kagaku-no-railgun and toaru-majutsu-no-index tag wiki excerpts use the romanizations "Rērugan" and "Indekkusu" respectively, while the tags themselves use the English analogues ("railgun" and "index"). Should we standardize on one style or the other for tags and tag wikis, and if so, which one?

Answer 1

I don't really think we need an official policy on this in general.

For most things other than tag names and possibly tag wikis, it's up to the post author what they want to use. So long as it's recognizable, I don't see a problem with either method of romanization. Often times if I'm using the Japanese name of a series I'll also use the English name since it's impossible to know which is more recognizable for most people.

For tag names, we usually prefer the English name if there is an official one that fits within 25 characters. If not, the goal is just to make it recognizable to the majority of people and search engines while retaining most of the keywords, though there are some guidelines for the best way to do this most of the time. Which is better is going to depend a lot on the series itself, but I suspect most of the time using the English word is going to be better for SEO and also in terms of fitting the title within 25 characters. For tag wikis, the most important purpose of these is to make it clear what the series is, so it probably makes sense to include all names by which the series is known.

Answer 2

Since this is an English language site, it only makes sense to use the English version of the words which are obviously supposed to be English. "Rērugan" and "Indekkusu" are obviously English words and not borrowed words.

For Tag names, I personally prefer to use kana spelling which makes it easier to type on regular US-101/104 style keyboards (using things like "ou" instead of "ō"). As for the name to use in anime/manga title tags, I personally prefer to use the name of an official westernized licensor (like "A certain scientific railgun"), just because most of the time it's easier to find for more casual fans, but it runs into the problem of other English speaking regions and their possibly (different) localization titles.