Open Content Syndication Directory Format (Version 0.1)

Introduction

Open Content Syndication (OCS) is an application of XML. It allows the definition of 'channels' of content and includes such information as the title and description of the content, the frequency of update and categorisation of the information. This format has arisen due to the popularity of channel formats such as Netscape's RSS format, which has led to the creation of a multitude of channels. This format is designed to enable channel listings to be constructed for use by portal sites, client based headline software and other similar applications.

For more information and feedback please contact iand@InternetAlchemy.org

Description of Format

The OCS format is specified in a DTD at http://InternetAlchemy.org/ocs/ocs-0.1.dtd. The following is a descriptive format of the elements and should be used in conjunction with the DTD when constructing client applications.

<ocs>

This mandatory element is the containing element for the list of channels.

<channel>

The mandatory channel element is the containing element for a syndicated channel.

<title>

This mandatory element describes the common title for the channel and should be used when a list of channels is displayed to the user.

<link>

This mandatory element contains a URL that links to the channel's home page.

<description>

This optional element is used to provide one or two paragraphs of descriptive text about the channel such as is purpose or goals.

<image>

This optional element specifies the location of an image or logo that should be used when displaying the channel to the user. It is recommended that it's dimensions should be 88 pixels wide by 31 pixels high.

<category>

This mandatory element defines the broad category of the channel. (These catagories are yet to be fuly defined)

<keywords>

There may be zero or more keyword elements which may contain any relevant words the channel producer deems applicable.

<contact>

There must be at least one contact element for each channel which contains a name and a URL that may be used to contact the owner of the channel. There may be additional contact elements but the first listed is always regarded as the primary contact.

<format>

This element defines the channel formats that the publisher makes available.. The currently defined types are:

RSS0.9 - the Netscape RSS format
ultramode - the ultramode format as used by slashdot
scriptingnews - the scriptingnews xml format as used by Scripting News and others
avantgo - the avantgo PDA format

Other formats may be added in future versions of the OCS format.

<update>

This element defines how frequently the channel content is updated. The period element defines the time period to which the frequency attribute is applied. The valid values for the period attribute are:

h - hour
d - day
w - week
m - month
y - year

So, for example, a period of 'd' and a frequency of 4, indicates that the channel is usually updated 4 times a day. A period of 'w' and a frequency of 1 means the channel is updated once a week. Note that the frequency attribute must be an integer value. This element also has an optional attribute called base. This specifies a base date and time from which the update frequency should be calculated. For example a base date of '22 Jun 1999 00:00:00 GMT', a period of 'h' and a frequency of 2 means that the content is updated every half an hour starting at midnight on the 22nd June. If the base date is in the future client applications should not fetch the channel until that date. Client applications should also randomly vary the exact time they fetch the channel content by a few minutes so as not to overload the publishing server.

OCS Example

<?xml version="1.0"?>
<!DOCTYPE ocs SYSTEM "http://InternetAlchemy.org/ocs/ocs-0.1.dtd">
<ocs>
  <channel>        
    <title>Internet Alchemy</title>
    <link>http://InternetAlchemy.org</link>
    <description>Internet Alchemy is a random collection of elements</description>
    <image>http://InternetAlchemy.org/images/alchemylogo.gif</image>
  
    <category>Tech News</category>
    <keyword>Java</keyword>  
    <keyword>XML</keyword>  
  
    <contact name="Ian Davis" link="mailto:alchemy@openjava.org" />
    
    <format type="RSS0.9" href="http://InternetAlchemy.org/alchemyrss.xml" />
    <format type="ultramode" href="http://InternetAlchemy.org/ultramode.txt" />
    <format type="scriptingnews" href="http://InternetAlchemy.org/scriptingnews.xml" />
    
    <update period="d" frequency="1" base="30 Mar 1999 00:00:00 GMT" />
  
  </channel>  

  <channel>
   ...
  </channel>
</ocs>

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