X.400 Basic Body Part,MIME content-type,Reference
ia5-text,text/plain;charset=us-ascii,[RFC1494]
voice,No Mapping Defined,[RFC1494]
g3-facsimile,image/g3fax,[RFC1494]
g4-class1,no mapping defined,[RFC1494]
teletex,no mapping defined,[RFC1494]
videotex,no mapping defined,[RFC1494]
encrypted,no mapping defined,[RFC1494]
bilaterally-defined,application/octet-stream,[RFC1494]
nationally-defined,no mapping defined,[RFC1494]
externally-defined,See Extended Body Parts,[RFC1494]