RSS enclosure

{{more citations needed|date=September 2017}}

RSS enclosures are a way of attaching multimedia content to RSS feeds with the purpose of allowing that content to be prefetched.{{cite web|url=https://www.rssboard.org/rss-enclosures-use-case|title=RSS Enclosures Use Case|website=Rssboard.org|access-date=3 October 2023}} Enclosures provide the URL of a file associated with an entry, such as an MP3 file to a music recommendation or a photo to a diary entry. Unlike e-mail attachments, enclosures are merely hyperlinks to files. The actual file data is not embedded into the feed (unless a data URL is used). 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 [http://backend.userland.com/rss092], was an important prerequisite for the emergence of podcasting, perhaps the most common use of the feature {{As of|2012|lc=on}}. In podcasts and related technologies enclosures are not merely attachments to entries, but provide the main content of a feed.