The AsciiDoc Working Group has been formed to write a complete and comprehensive specification: https://asciidoc-wg.eclipse.org/

If you are interested in an AsciiDoc processor in Haskell, you can read: https://www.tweag.io/blog/2021-06-15-asciidoc-haskell-pandoc...

We had Guillem Marpons at the last AsciiDoc WG meeting and he was willing to work toward a spec-compliant implementation and help us with the spec.