`text`. The message part contains information in textual format. There are several subtypes : `text/plain` for regular ASCII text, `text/html` defined in :rfc:`2854` for documents in :term:`HTML` format or the `text/enriched` format defined in :rfc:`1896`. The `Content-Type:` header line may contain a second parameter that specifies the character set used to encode the text. `charset=us-ascii` is the standard ASCII character table.Other frequent character sets include `charset=UTF8` or `charset=iso-8859-1`. The `list of standard character sets <http://www.iana.org/assignments/character-sets>`_ is maintained by :term:`IANA`.