Adding new languages to the language list

Is there any way to add new languages to show more accurately the language that a book is written in or that it uses a lot of ('Secondary language') or that it's been translated from ('Original language')?

Currently, with my interests in linguistics and anthropology, I have to use inaccurate approximations eg 'Austronesian (other)' when what I want is, say, Proto-Austronesian or Austronesian or Polynesian or Oceanic.

I expect you have to go through here

Mmmm, looks a bit technical for my needs. I'm just wanting to improve the LT list of languages to make more accurate my description of a relevant book or article.

I think message 2 means that LT is using the generated list of languages from Library of Congress.
So, if LoC don't have it defined in their language list and use it in cataloging, then LT doesn't have it as a language either.

And no way around it? (I notice for instance that some people manage to get around the list of secondary authors and add new functions such as 'Co-author'.)

I think that the Co-author functionality only exists for newly added books. It was introduced towards the end of last year and said at that time that it would be retrospectively added to other books.

Maybe sometime soon, maybe not.

Probably your best bet is to use tags to distinguish languages. In my library I tag by language family (or para-linguistic macro-family) such as IE, austronesian, romance, amerind and then by language.

Yes that's pretty well what I've been doing but I thought it would be nice to be able to show languages more accurately in the formal space provided. Thanks for the comments, everyone.

Interestingly enough, when I got a Dayak dictionary the other day, Dayak was in the list when I was manually entering the book. It only showed after I clicked 'show all languages'.

when what I want is, say, Proto-Austronesian

You have books in Proto-Austronesian? I'm jealous!

Just lexical items marked with an *!