Request for review of CEA Task Model Description media type: application/cea-2018+xml

Gottfried Zimmermann gzimmermann at
Thu Jul 17 09:47:51 CEST 2008

The Consumer Electronics Association (CEA) has released standard CEA-2018 on
Task Model Descriptions (see  

A task model is a formal description of the activities involved in
completing a task, including both activities carried out by humans and those
performed by machines.  CEA-2018 defines the semantics and an XML notation
for task models relevant to consumer electronics devices.  

CEA is requesting to assign the MIME type "application/cea-2018+xml" to Task
Model Descriptions based on CEA-2018.

See below for the registration request.  Any comments/concerns are welcome.

Gottfried Zimmermann
Editor of CEA-2018

PS: This registration request is a modification of a previous version
which never got followed up.  The new text has additional wording addressing
possible security concerns about the inclusion of ECMAScript fragments in
Task Model Descriptions.


Registration Request:

Type name: application

Subtype name: cea-2018+xml

Required parameters: none

Optional parameters: none

   Note that (in contrast to application/xml) no charset parameter is
defined since CEA-2018 specifies UTF-8 as the required file format.

Encoding considerations: Same as encoding considerations of application/xml
as specified in RFC 3023.

Security considerations: All of the security considerations described in RFC

  Additionally, the inclusion of ECMAScript fragments (so-called "active
content") in a CEA-2018 document bears risks in that a task-based
application may execute malicious or erroneous ECMAScript code as part of a
task model embedded condition or grounding statement.  However, a task-based
application will typically execute this code in sandbox and can thus prevent
potential damage to local and other resources.  Note that the embedded
ECMAScript code fragments pose only minimal additional security risks for
Web browsers since ECMAScript code is only embedded as content of XML
elements other than <script>.
  The general utility of this media type to the Internet community is in the
area of user interfaces for consumer electronics (and other areas of devices
and services).  Task models facilitate user interfaces that can be easier to
use than traditional user interfaces.  Task models can thus be discovered
and shared over the Internet (and local home networks), and be uniquely
identified as such by the receiving entity.

Interoperability considerations: Same as interoperability considerations of
text/xml as specified in RFC 3023.

Published specification: CEA-2018

Applications that use this media type: Task-based applications, i.e.
programs that interpret task model descriptions according to the semantics
defined in CEA-2018.

Additional information:

  Magic number(s): Same as magic number(s) of text/xml as specified in RFC
  File extension(s): .xml
  Macintosh file type code(s): "TEXT"

Person & email address to contact for further information: 
   Gottfried Zimmermann <gzimmermann at>

Intended usage: COMMON

Restrictions on usage: none

Author: CEA-2018 is a standard by the Consumer Electronics Association
(CEA), and was edited by:
   Gottfried Zimmermann <gzimmermann at>

Change controller: CEA R7 and its working group 12 have change control over

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