A list of links to external files associated with this entry.
Some aggregators automatically download enclosures (although this technique has known problems). Some aggregators render each enclosure as a link. Most aggregators ignore them.
The RSS specification states that there can be at most one enclosure per item. However, because some feeds break this rule, Universal Feed Parser captures all of them and makes them available as a list.
The URL of the linked file.
If this is a relative URI, it is resolved according to a set of rules.