X.400 1988 to 1984 downgrading

This document considers issues of downgrading from X.400(1988) to X.400(1984) [MHS88a, MHS84]. Annexe B of X.419 specifies some downgrading rules [MHS88b], but these are not sufficient for provision of service in an environment containing both 1984 and 1988 components. This document defines a number of extensions to this annexe. [STANDARDS-TRACK]