You can find the current standards-track drafts of the EDI-INT Requirements document, as well as AS2 specifications, at the following web sites:
For MIME-based secure peer-to-peer business data interchange over the Internet:
http://www.ietf.org/rfc/rfc3335.txt?number=3335
For HTTP transport for secure peer-to-peer business data interchange over the Internet:
http://www.ietf.org/proceedings/02jul/I-D/draft-ietf-ediint-as2-11.txt
http://www.ietf.org/proceedings/02mar/I-D/draft-ietf-ediint-as2-10.txt