The name of the repository. The name may contain spaces and punctuation. An indication of when the repository was last changed. Client's can check if a repository has been updated by checking this increment value. Describes a general resource with requirements and capabilities. A referral points to another repository XML file. The purpose of this element is to create a federation of repositories that can be accessed as a single repository. The depth of referrals this repository acknowledges. The URL to the referred repository. The URL can be absolute or relative from the given repository’s URL. A named set of type attributes and directives. A capability can be used to resolve a requirement if the resource is included. Name space of the capability. Only requirements with the same name space must be able to match this capability. A filter on a named set of capability attributes. Name space of the requirement. Only capabilities within the same name space must be able to match this requirement. A named value with an optional type that decorates a requirement or capability. The name of the attribute. The value of the attribute. The type of the attribute. A named value of type string that instructs a resolver how to process a requirement or capability. The name of the directive. The value of the directive. This attribute should be used by extensions to documents to require that the document consumer understand the extension. This attribute must be qualified when used.