RFC 1154 (rfc1154) - Page 2 of 7
Encoding header field for internet messages
Alternative Format: Original Text Document
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
