Media subtype name
            html

    Required parameters
            none





 
RFC 1866            Hypertext Markup Language - 2.0        November 1995


    Optional parameters
            level, charset

    Encoding considerations
            any encoding is allowed

    Security considerations
            see 10, "Security Considerations"

    The optional parameters are defined as follows:

    Level
            The level parameter specifies the feature set used in
            the document. The level is an integer number, implying
            that any features of same or lower level may be present
            in the document. Level 1 is all features defined in this
            specification except those that require the 
            element. Level 2 includes form processing. Level 2 is
            the default.

    Charset
            The charset parameter (as defined in section 7.1.1 of
            RFC 1521[MIME]) may be given to specify the character
            encoding scheme used to represent the HTML document as a
            sequence of octets. The default value is outside the
            scope of this specification; but for example, the
            default is `US-ASCII' in the context of MIME mail, and
            `ISO-8859-1' in the context of HTTP [HTTP].

4.2. HTML Document Representation

   A message entity with a content type of `text/html' represents an
   HTML document, consisting of a single text entity. The `charset'
   parameter (whether implicit or explicit) identifies a character
   encoding scheme. The text entity consists of the characters
   determined by this character encoding scheme and the octets of the
   body of the message entity.

4.2.1. Undeclared Markup Error Handling

   To facilitate experimentation and interoperability between
   implementations of various versions of HTML, the installed base of
   HTML user agents supports a superset of the HTML 2.0 language by
   reducing it to HTML 2.0: markup in the form of a start-tag or end-
   tag, whose generic identifier is not declared is mapped to nothing
   during tokenization. Undeclared attributes are treated similarly. The
   entire attribute specification of an unknown attribute (i.e., the
   unknown attribute and its value, if any) should be ignored. On the




 
RFC 1866            Hypertext Markup Language - 2.0        November 1995


   other hand, references to undeclared entities should be treated as
   data characters.

   For example:

    <div class=chapter>foo...
      => ,"foo",,,"..."
    xxx  yyy
      => "xxx ",," yyy
    Let α & β be finite sets.
      => "Let α & β be finite sets."

   Support for notifying the user of such errors is encouraged.

   Information providers are warned that this convention is not binding:
   unspecified behavior may result, as such markup does not conform to
   this specification.

4.2.2. Conventional Representation of Newlines

   SGML specifies that a text entity is a sequence of records, each
   beginning with a record start character and ending with a record end
   character (code positions 10 and 13 respectively) (section 7.6.1,
   "Record Boundaries" in [SGML]).

   [MIME] specifies that a body of type `text/*' is a sequence of lines,
   each terminated by CRLF, that is, octets 13, 10.

   In practice, HTML documents are frequently represented and
   transmitted using an end of line convention that depends on the