RFC 1154 (rfc1154) - Page 2 of 7

Encoding header field for internet messages

RFC 1154      Encoding Header Field for Internet Messages     April 1990


     [ [], ]* []  []

     where:

           := a decimal integer
         := a single alphanumeric token starting with an alpha
         := keyword-dependent options

3.2. 

   The line count is a decimal number specifying the number of text
   lines in the part.  Parts are separated by a blank line, which is not
   included in the count of either the proceeding or following part.
   Because a count always begins with a digit and a keywords always
   begins with an letter, it is always possible to determine if the
   count is present.  (The count is first because it is the only
   information of interest when skipping over the part.)

   The count is not required on the last or only part.

3.3. 

   The keyword defines the encoding type.  The keyword is a common
   single word name for the encoding type.  The keywords are not case-
   sensitive.

   The list of standard keywords is intended to be the same as the list
   used for the Content-Type: header described in [6].  This RFC
   proposes additions to the list.  Implementations can then treat
   "Content-Type" as an alias of "Encoding", which will always have only
   one body part.

3.4. 

   The optional information is used to specify additional keyword-
   specific information needed for interpreting the contents of the
   encoded part.  It is any sequence of tokens not containing a comma.

3.5. Encoding Version Numbers

   In general, version numbers for encodings, when not actually
   available within the contents of the encoded information, will be
   handled as options.

3.6. Comments

   Comments enclosed in parentheses may, of course, be inserted anywhere
   in the Encoding field.  Mail reading systems may pass the comments to



Robinson & Ullmann