On Jan 9, 2011, at 2:16 PM, Jurko Gospodnetić wrote:
> In an element such as:
>
> <guid isPermaLink="true">XXX</guid>
>
> XXX must be a valid link that can be used by a web browser to access the item's data.
In particular, the spec:
http://www.rssboard.org/rss-specification
says that the "Link" in "isPermaLink" is key here:
<guid> is an optional sub-element of <item>.
guid stands for globally unique identifier. It's a string that uniquely identifies the item. When present, an aggregator may choose to use this string to determine if an item is new.
<guid>http://some.server.com/weblogItem3207</guid>
There are no rules for the syntax of a guid. Aggregators must view them as a string. It's up to the source of the feed to establish the uniqueness of the string.
If the guid element has an attribute named isPermaLink with a value of true, the reader may assume that it is a permalink to the item, that is, a url that can be opened in a Web browser, that points to the full item described by the <item> element. An example:
<guid isPermaLink="true">http://inessential.com/2002/09/01.php#a2</guid>
isPermaLink is optional, its default value is true. If its value is false, the guid may not be assumed to be a url, or a url to anything in particular.