RFC 1806 (rfc1806) - Page 3 of 8

Communicating Presentation Information in Internet Messages: The Content-Disposition Header

RFC 1806                  Content-Disposition                  June 1995


2.1  The Inline Disposition Type

   A bodypart should be marked `inline' if it is intended to be
   displayed automatically upon display of the message. Inline bodyparts
   should be presented in the order in which they occur, subject to the
   normal semantics of multipart messages.

2.2  The Attachment Disposition Type

   Bodyparts can be designated `attachment' to indicate that they are
   separate from the main body of the mail message, and that their
   display should not be automatic, but contingent upon some further
   action of the user. The MUA might instead present the user of a
   bitmap terminal with an iconic representation of the attachments, or,
   on character terminals, with a list of attachments from which the
   user could select for viewing or storage.

2.3  The Filename Parameter

   The sender may want to suggest a filename to be used if the entity is
   detached and stored in a separate file. If the receiving MUA writes
   the entity to a file, the suggested filename should be used as a
   basis for the actual filename, where possible.

   It is important that the receiving MUA not blindly use the suggested
   filename.  The suggested filename should be checked (and possibly
   changed) to see that it conforms to local filesystem conventions,
   does not overwrite an existing file, and does not present a security
   problem (see Security Considerations below).

   The receiving MUA should not respect any directory path information
   that may seem to be present in the filename parameter.  The filename
   should be treated as a terminal component only.  Portable
   specification of directory paths might possibly be done in the future
   via a separate Content-Disposition parameter, but no provision is
   made for it in this draft.

   Current [RFC 1521] grammar restricts parameter values (and hence
   Content-Disposition filenames) to US-ASCII.  We recognize the great
   desirability of allowing arbitrary character sets in filenames, but
   it is beyond the scope of this document to define the necessary
   mechanisms.  We expect that the basic [RFC 1521] `value'
   specification will someday be amended to allow use of non-US-ASCII
   characters, at which time the same mechanism should be used in the
   Content-Disposition filename parameter.






Troost & Dorner               Experimental