a) SQLite the file format - which is Public Domain and so well documented that parsers for it exist in numerous other languages even though it's almost pointless because...
b) SQLite, the Public Domain (and thus entirely source available) C implementation of the library that can operate on the file format -- and is documented to a level well above what most ISO standards shoot for. It's designed to be used in other software and has bindings for pretty much every major language.
c) Some notional OpenDocument stored in a SQLite file that's really just waiting for somebody to make and document.
ISO standards are great, but if we had to wait for ISO to define a file format we'd have pitifully little to work with.