RE: Why does app:collection contain multiple app:categories?

["Brian Smith" <brian@xxxxxxxxxxxxxx>]

John Stracke wrote:
> In 5023, section 8.3.3, it's specified that an 
> <app:collection> element MAY contain any number of 
> <app:categories> elements.  Why? An <app:categories> is 
> already a list; what does it mean if we have more than one?

(1) If you have multiple category documents, then you need to use
multiple app:categories elements to link to them. 

(2) If you are using multiple schemes, you might choose to use place
each scheme's categories in a separate app:categories element and let
the atom:category elements inherits their @scheme from the app:category
element.

> It's worth noting that 8.3.6 seems to think that there should 
> be only one <app:categories>: "The "app:categories" element 
> provides a list of the categories that can be applied to the 
> members of a Collection."

That is a minor editorial issue; replace "element provides" with
"elements provide". 

Another confusion comes from the @fixed attribute. The set of categories
is fixed if any app:categories element has @fixed='yes', even if other
app:categories elements have an explicit @fixed='no'. This was discussed
on the list about a month ago.

- Brian