RFC2318

Network Working Group H. Lie Request for Comments: 2318 B. Bos Category: Informational C. Lilley

                                                                 W3C
                                                          March 1998

                    The text/css Media Type

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1998). All Rights Reserved.

Abstract

Cascading Style Sheets (CSS) is a style sheet language for the World Wide Web. CSS style sheets have been in use since October 1995 using the Media Type text/css without registration; this memo seeks to regularize that position.

Introduction

The World Wide Web Consortium has issued a Recommendation [1], which defines Cascading Style Sheets, level 1. This memo provides information about the text/css Media Type.

Cascading Style Sheets

Cascading Style Sheets (CSS) is a style sheet language for the World Wide Web. It describes the presentation (e.g. fonts, colors and spacing) of structured documents. CSS is human readable and writable, and expresses style in common desktop publishing terminology.

CSS style sheets have been in use since October 1995 using the Media Type text/css without registration; this memo seeks to regularize that position.

A CSS style sheet can be either:

(1) external - the style sheet is linked to a document through a

   URI and exists as a separate object on the Web. The media type
   text/css is used when fetching the object, for example in the
   Content-Type and Accept header fields of HTTP [2].

(2) internal - the style sheet is contained within the document. A

   typical scenario is an HTML [3] document that contains a style
   sheet within the STYLE element. Due to this close relationship,
   HTML and CSS share the same top-level name ("text").

Registration Information

   To: [email protected]
   Subject: Registration of MIME media type text/css

   MIME media type name: text

   MIME subtype name: css

   Required parameters: none

   Optional parameters: charset

   The syntax of CSS is expressed in US-ASCII, but a CSS file can
   contain strings which may use any Unicode character. Any charset
   that is a superset of US-ASCII may be used; US-ASCII, iso-8859-X
   and utf-8 are recommended.

Encoding considerations:

   For use with transports that are not 8-bit clean, quoted-
   printable encoding is recommended since the majority of
   characters will be CSS syntax and thus US-ASCII

Security considerations:

   Applying a style sheet to a document may hide information
   otherwise visible. For example, a very small font size may be
   specified, or the display of certain document elements may be
   turned off.

   CSS style sheets consist of declarative property/value pairs
   assigned to element selectors. They contain no executable code.

   As with HTML documents, CSS style sheets may contain links to
   other media (images, sounds, fonts, other style sheets) and those
   links are typically followed automatically by software, resulting

   in the transfer of files without the explicit request of the user
   for each one. The security considerations of each linked file are
   those of the individual registered types.

Interoperability considerations:

   CSS has proven to be widely interoperable across computer
   platforms, across Web browsers of different makes, and for import
   and export in multiple authoring tools.

Published specification: see [1]

Applications which use this media type:

   CSS is device-, platform- and vendor-neutral and is supported by
   a wide range of Web user agents and authoring tools for
   formatting HTML and XML documents.

Additional information:

   Magic number(s): none
   File extension(s): .css
   Macintosh File Type Code(s): "css "
   Object Identifier(s) or OID(s): none

Person & email address to contact for further information:

   The authors of this memo.

Intended usage: COMMON

 Author/Change controller:

References

[1] Lie, H., and B. Bos, "Cascading Style Sheets, level 1",

    W3C Recommendation REC-CSS1-961217, http://www.w3.org/TR/REC-
    CSS1-961217, December 1996.

[2] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T.

    Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC
    2068, January 1997.

[3] Raggett, D., Le Hors, A. and I. Jacobs, "HTML 4.0

    Specification", W3C Recommendation REC-html40-971218,
    http://www.w3.org/TR/REC-html40, December 1997.

Authors' Addresses

Hakon Lie W3C/INRIA 2004, route des Lucioles - B.P. 93 06902 Sophia Antipolis Cedex FRANCE

Phone: +33 (0)492387771 Fax: +33 (0)493657765 EMail: [email protected]

Bert Bos 2004, route des Lucioles - B.P. 93 06902 Sophia Antipolis Cedex FRANCE

Phone: +33 (0)492387692 Fax: +33 (0)493657765 EMail: [email protected]

Chris Lilley 2004, route des Lucioles - B.P. 93 06902 Sophia Antipolis Cedex FRANCE

Phone: +33 (0)492387987 Fax: +33 (0)493657765 EMail: [email protected]

Full Copyright Statement

Copyright (C) The Internet Society (1998). All Rights Reserved.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

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