When did LOC adopt modified Hepburn?


If I look in Google Ngrams, I see that the transliteration "honbu", meaning
HQ, basically didn't exist until 1964. But it didn't surpass "hombu" until
1976. I believe Modified Hepburn was introduced in the 1950s, but I am
wondering when the Library of Congress adopted it as an ALA standard--in maybe
the early 1970s? I can't find any dates for this information, though I have
looked on the LOC website.




1983.

In the deepest corners of the Library of Congress website, you can find the
[Spring 1983 issue of the Cataloging Service
Bulletin](https://www.loc.gov/aba/publications/FreeCSB/CSB_020.pdf). On page
51, you can see the specification calling for the modified Hepburn system for
romanization.

An excerpt of the paragraph:

> The modified Hepburn system of romanization as employed in **Kenkyusha's New
> Japanese-English Dictionary** (3rd and later editions) is used. For the
> syllabic nasal, "n" is always used preceding "b," "m," and "p." Romanization
> for words of foreign origin follows the American National Standard system
> for the romanization of Japanese, e.g., ベトナム Betonamu; ヴェトナム Vetonamu.

