http://www.rfc-editor.org/rfc/rfc2440.txt
RFC 2440: OpenPGP Message Format, J. Callas, L. Donnerhacke, H. Finney, R. Thayer1998-11-01T23:00:00-00:00This document is maintained in order to publish all necessary information needed to develop interoperable applications based on the OpenPGP format. [STANDARDS-TRACK]