protected content

How can the type of protected information be identified in s/mime.
 
It is the intention of the S/MIME specification to be used to protect 
information which is encoded in any form,  not just using MIME.  If believe the 
convention in CMS is,  when multi S/MIME wrapping is performed the inner most 
content is identified a "id-data" in contentType attribute.  This gives no clue 
as to the encoding or type of the information which being protected. Does 
anyone agree that it would be useful to identify the type and encoding of the 
protected information? or do you disagree? or is if you think it is currently 
identified , how is this done?
 
In some off-line discussion it was proposed that the contentHints attribute as 
defined in ESS may be used for this purpose. Also , the ess-02 draft eluded to 
an attribute called "encapsulatedContentType" which may have been intended to 
meet this requirement. 
 
I think the title of contentHints is wrong if is used for this purpose, second 
as defined currently it is not up to the job.
 
If the above is agree, a new type of attribute is should be defined replacing 
contentHints.
The following is a starter for ten based on renaming and extending the current 
"contentHints"  and using some of the old "encapsulatedContentType" syntax.
 
ProtectedInformationTypeAttribute ::= SEQUENCE {
  contentDescription [0] IMPLICIT OCTET STRING SIZE (1..MAX) OPTIONAL,
    -- If contentDescription is used, its contents MUST be in UTF8 format
  contentType [1] ContentType OPTIONAL
  protectedContentType [2} ProtectedContentType OPTIONAL }


ContentType is a defined by CMS
ProtectedContentType ::= CHOICE {
  built-in BuiltinContentType,
  external ExternalContentType,
  externalWithSubtype ExternalContentWithSubtype }

BuiltinContentType ::= [APPLICATION 6] INTEGER {
    -- APPLICATION 6 is used for binary compatibility with X.411
  unidentified (0),
  external (1),
  interpersonal-messaging-1984 (2),
  interpersonal-messaging-1988 (22),
  edi-messaging (35),
  voice-messaging (40)} (0..ub-built-in-content-type)

ub-built-in-content-type INTEGER ::= 32767

ExternalContentType ::= OBJECT IDENTIFIER

ExternalContentWithSubtype ::= SEQUENCE {
  external ExternalContentType,
  subtype OCTET STRING}

Any Comments?