RSS enclosure

Unlike e-mail attachments, enclosures are merely hyperlinks to files.

Support and implementation among aggregators varies: if the software understands the specified file format, it may automatically download and display the content, otherwise provide a link to it or silently ignore it.

The addition of enclosures to RSS, as first implemented by Dave Winer in late 2000 [1], was an important prerequisite for the emergence of podcasting, perhaps the most common use of the feature as of 2012[update].

In podcasts and related technologies enclosures are not merely attachments to entries, but provide the main content of a feed.

In RSS 2.0, the syntax for the tag, an optional child of the element, is as follows: where the value of the url attribute is a URL of a file, length is its size in bytes, and type its mime type.