Today I bought a hundred year old book in a secondhand bookshop in Naha, Okinawa. It's a handbook of the Ryukyuan language in Japanese, though it has both Japanese and English titles there is no English inside.
This is how it describes itself in English
Being a Guide to Conversations in the Standard
Luchuan, to which is added 琉語解釋 written
by Giwan Chōho the last Statesman
of old Luchu,
The Japanese I've shown it to could not guess what 琉語解釋 means. The first two characters are obviously an abbreviated way to say "Ryukyuan language" (琉球語 would be unabbreviated) but the last two characters baffled them.
Since this book is from the prewar era it must use 旧字体, older kanji forms before the simplified characters were introduced and many other characters were more or less deprecated in the language reforms / standardization.
But another strange thing is that the book does not use the usual English terms "Ryukyu" and "Ryukyuan" but very Chinese-looking terms "Luchu" and "Luchuan".
This makes me wonder if this particular phrase might actually be Chinese rather than Japanese?