When editing a .wav file in Sony Sound Forge, it gives the option of including the "acid" information inside the file. This is supposed to tell "any software that understands the wav file structure" to know that the file contains a loop and what kind of loop it is.

That sounds all nice unless you actually write software that reads/writes .wav files. Contrary to Sony's hype the "acid" subchunk is not included in the official wav file structure. And searching the web for its structure is nothing but frustration.

If you search for wav files, you can find many sites describing its structure but none of them mentions the "acid" subchunk.

If you include the word "acid" in your search, you just get a listing of gadzillion sites on chemistry (this is a common problem with the software industry's love for names that have a common meaning that has nothing to do with their software).

So, I am hoping someone here knows, and will tell me, what exactly the structure of the data hidden in the "acid" subchunk of a .wav file is. Thanks!

Yes, but what is its structure? In other words, how do I (as a programmer) extract that metadata? Or, how can I write it to a .wav file that I create?

Most of my synthesized files here are created directly by software that I write. But without knowing the specification of that chunk, I cannot write the chunk to my loops, even though it would make them more useful.