Postby thegooseking » July 14th, 2014 8:52 am
buckさん,
I'm not sure what they're called in Japan, but I would guess that their distinguishing feature is not that they are contemporary, but that they are used exclusively to render non-Japanese words.
Therefore I would call them 外来語カタカナ ("gairaigo katakana") - katakana that is used in loanwords (although you're right that it's only used in loanwords that have recently entered Japanese - older loanwords are more often conformed to Japanese phonology).
These digraphs come from several reports by the Japanese government in the 20th century on how to write gairaigo words, most notably the Bunkachō's (文化庁; Agency for Cultural Affairs) 1991 report 外来語の表記 (gairaigo no hyōki; "Orthography of Loanwords").
Although you asked for the correct term, and I can't promise that that is correct. It's just a guess.
小狼
