• Syllabic nasal: ん (n)
Since ん has been romanized differently throughout the years, it is best to check two ways of romanizing it:
(1) ん = n before m, b, and p
ex: しんぶん = shinbun ほんま = honma
(2) ん = n before p, and m before b
ex: しんぶん = shimbun ほんま = homma
You will probably find more records for type (1), but please be aware that some older records will use type (2) instead.
• Long vowels and Diacritics: おお, おう, ええ, うう (oo, ou, ee, uu / ō, ō, ē, ū)
Double vowels (oo, ou, ee, uu) are not used in the catalog (with two exceptions, see below), but instead are represented by single vowels with long marks over them (ō, ō, ē, ū). However, when you search the catalog, you can ignore these long marks, and simply type single vowels.
ex: きのう = kinō = kino
ex: おおさか = ōsaka = osaka
ex: きゅうしゅう = kyūshū = kyushu
Exception 1: use the double ii for adjectival forms and other words.
ex: おおきい = ōkii = okii
ex: かなしい = kanashii
ex: きいろい = kiiroi
Exception 2: when う appears as a verb ending after another vowel, type both vowels.
ex: おもう (思う) = omou
ex: すう (吸う) = suu
• Double consonants (geminate consonants): using small つ (小さい「つ」)
Double consonants are marked by doubling the consonant following the つ, except in the case of し, ち, and つ.
ex: ちょっと = chotto
ex: いっぴき = ippiki
し → ssh ex: まっしろい = masshiroi
ち → tch ex: あっち / こっち = atchi / kotchi
つ → tts ex: よっつ = yottsu
NOTE: In the case of 日本 as "Nihon" vs. "Nippon", try both if you are unsure of the reading.
• Particles: へ, は, を (e, wa, o)
When へ, は, and を are used as particles, they are romanized
へ = e は = wa を = o
江戸川乱歩 Edogawa, Ranpo/Rampo
村山槐多 Murayama, Kaita
黒岩涙香 Kuroiwa, Ruikō/Ruiko
小酒井不木 Kozakai/Kosakai, Fuboku
横溝正史 Yokomizo, Seishi
甲賀三郎 Kōga/Koga, Saburō/Saburo
久山秀子 Hisayama, Hideko
浜尾四郎 Hamao, Shirō/Shiro
夢野久作 Yumeno, Kyūsaku/Kyusaku
久志芙沙子/富佐子 Kushi, Fusako