Wiktionary:Japanese transliteration

Transliteration of the Japanese Language
The basis for Wiktionary's romanization of Japanese (called or  in Japanese) is the Hepburn system. Other than the rules elaborated below, all Japanese text should follow the Hepburn romanization charts on Wikipedia (this does not include the rules qualifying those charts that are also listed above in the same article). Draft Note: Wiktionary employs some modifications to Hepburn that are not included in Wikipedia, particularly with regard to the use of to romanize  (the long "i" sound).

There are two sets of rules qualifying these charts. The first is the "strict" set, to be followed in article titles and the like for maximum consistency, and the second is the "relaxed" set, which can be used in running text for improved readability.

Strict rules

 * Every word in Japanese must be expressed as a single romanized "word", with no spaces or hyphens.
 * A word, in this context, is a single sentence component. This does not include particles, called, nor compound nouns, which are treated separately. Conjugated forms are counted as a single word, whereas verbs consisting of  affixed to a noun treat the  separately. The following illustrates some examples, with appropriate romanization in parentheses:
 * Each word must be separated from other words by spaces.
 * 書式を意識して書きます (shoshiki o ishiki shite kakimasu).
 * The character は, when used as a particle, must be transliterated as wa instead of ha.
 * これは例文です (kore wa reibun desu)
 * The character を, when used as a particle, must be transliterated as o instead of wo.
 * When used in proper nouns, including person and place names, it must be transliterated as o unless it is customary to transliterate that person's or place's name as wo.
 * The character へ, when used as a particle, must be transliterated as e instead of he.
 * 日本へ行きたい (Nihon e ikitai), exception: へんたい (hentai)
 * The character ん, when followed in the same word by a vowel (あ, い, う, え, or お) or semivowel "y" mora (や, ゆ, よ), must be transliterated as n' instead of just n.
 * 近縁 (きんえん, kin'en), as opposed to 近年 (きんねん, kinnen) and 記念 (きねん, kinen)
 * 金融 (きんゆう, kin'yū), as opposed to 記入 (きにゅう, kinyū)
 * Exception: This does not apply to "w" mora (わ, ウィ, ウェ, ウォ). Instead, a rare "nw" mora (ヌァ, ヌィ, ヌェ, ヌォ), must begin &apos;nw instead of just nw.
 * ルブヌィ (Rubu'nwi), as opposed to おんわ (onwa) or コンウィ (Konwi)
 * Any symbol followed by ー (the chōonpu) indicates that the vowel is long and it is transliterated by using the vowel with a macron over it (ā, ē, ī, ō, ū).
 * らーめん (rāmen), ビー玉 (ビーだま, bīdama), スーツ (sūtsu), ケーキ (kēki), オーケストラ (ōkesutora).
 * Any syllable ending in the お (o) sound that is followed by う in the same word must be considered a "long o" and transliterated as ō.
 * 交差点 (こうさてん, kōsaten) and ありがとう (arigatō)
 * Exception: if there is a morphemic break between お and う, おう should be transliterated ou. For example:
 * If the う is the final syllable in a verb, and thus transformed to another syllable as a result of conjugation: 誘う (さそう, sasou).
 * In compound terms, such as 牡牛 (おうし, oushi) and 牡馬 (おうま, ouma).
 * ああ (aa), いい (ii), うう (uu), ええ (ee) and おお (oo) combinations are considered long vowel forms and are transliterated as ā, ī, ū, ē and ō respectively.
 * Exception: If there is a morpheme boundary, then both vowels must be written.
 * お母さん (おかあさん, okāsan), らーめん (rāmen), and 逆上がり (さかあがり, sakaagari).
 * 姉さん (ねえさん, nēsan), exceptions: 濡れ縁 (ぬれえん, nureen) and ケーキ (kēki).
 * 新潟 (にいがた, Nīgata), ビー玉 (ビーだま, bīdama), and 言い (ii).
 * 大騒ぎ (おおさわぎ, ōsawagi), exceptions: 呉音 (ごおん, goon) and 女王 (じょおう, joō).
 * 十 (じゅう, jū), exceptions: 食う (くう, kuu) and 風雲 (ふううん, fūun).
 * っ (the sokuon, a.k.a. little tsu) must be transliterated as a doubling of the initial consonant of the following character. If there is no following character, then it is transliterated as an apostrophe (write  to escape from markups).
 * 喫茶店 (きっさてん, kissaten), って (tte), あっ (a&apos;)
 * Exceptions:
 * If the sokuon precedes the chi kana (ち/チ), do not use "cchi" and instead use "tchi" (or the equivalent yōon, e.g. tcha、tcho, etc.): しょっちゅう (shotchū).
 * If the sokuon precedes an "n" (ナ, ニ, ヌ, ネ, ノ) or "m" mora (マ, ミ, ム, メ, モ), transliterate it using an apostrophe: ハガッニャ (Haga'nya), トッモ (to'mo).
 * Japanese punctuation can be romanized with the closest equivalent English punctuation: . for . ; ,　for 、; " for 「 or 」; etc.
 * 行きましょうか. Ikimashō ka.
 * ポテチを取り、食べる. Potechi o tori, taberu.
 * Exceptions:
 * If the sokuon precedes the chi kana (ち/チ), do not use "cchi" and instead use "tchi" (or the equivalent yōon, e.g. tcha、tcho, etc.): しょっちゅう (shotchū).
 * If the sokuon precedes an "n" (ナ, ニ, ヌ, ネ, ノ) or "m" mora (マ, ミ, ム, メ, モ), transliterate it using an apostrophe: ハガッニャ (Haga'nya), トッモ (to'mo).
 * Japanese punctuation can be romanized with the closest equivalent English punctuation: . for . ; ,　for 、; " for 「 or 」; etc.
 * 行きましょうか. Ikimashō ka.
 * ポテチを取り、食べる. Potechi o tori, taberu.

Relaxed rules

 * If a compound word can be broken into discrete parts, especially when one of the parts is a common prefix or suffix, use a hyphen to separate the parts.
 * Exception: if the word is very short, or the prefix or suffix is strongly associated with the word: ,
 * If a particle or suffix is strongly associated with the preceding word, it is acceptable to use a hyphen instead of a space.
 * If a sentence is a question, a question mark should be used in the romanization. If it is unclear whether the sentence is a question (e.g., ), the question mark is optional, and should probably be omitted.
 * However, when a question mark is used in the Japanese, a question mark should also be used in the romanization: e.g.,
 * If a particle or suffix is strongly associated with the preceding word, it is acceptable to use a hyphen instead of a space.
 * If a sentence is a question, a question mark should be used in the romanization. If it is unclear whether the sentence is a question (e.g., ), the question mark is optional, and should probably be omitted.
 * However, when a question mark is used in the Japanese, a question mark should also be used in the romanization: e.g.,
 * However, when a question mark is used in the Japanese, a question mark should also be used in the romanization: e.g.,

la:Auxilium:Romanizatio Iaponica