RSS enclosures are a way of attaching

multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradi ...

content to

RSS RSS ( RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a standardized, computer-readable format. Subscribing to RSS feeds can allow a user to keep track of many di ...

feeds by providing the

URL A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifi ...

of a file associated with an entry, such as an

MP3 MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Orig ...

file to a music recommendation or a photo to a diary entry. Unlike

e-mail attachment An email attachment is a computer file sent along with an email message. One or more files can be attached to any email message, and be sent along with it to the recipient. This is typically used as a simple method to share documents and images. H ...

s, enclosures are merely

hyperlink In computing, a hyperlink, or simply a link, is a digital reference to data that the user can follow or be guided by clicking or tapping. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text ...

s to files. The actual file data is not

embedded Embedded or embedding (alternatively imbedded or imbedding) may refer to: Science * Embedding, in mathematics, one instance of some mathematical object contained within another instance ** Graph embedding * Embedded generation, a distributed ge ...

into the feed (unless a

data URL The data URI scheme is a uniform resource identifier (URI) scheme that provides a way to include data in-line in Web pages as if they were external resources. It is a form of file literal or here document. This technique allows normally separat ...

is used). Support and implementation among aggregators varies: if the software understands the specified

file format A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...

, it may automatically

download In computer networks, download means to ''receive'' data from a remote system, typically a server such as a web server, an FTP server, an email server, or other similar system. This contrasts with uploading, where data is ''sent to'' a remo ...

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 Dave Winer (born May 2, 1955, in Queens, New York City) is an American software developer, entrepreneur, and writer who resides in New York City. Winer is noted for his contributions to outliners, scripting, content management, and web servic ...

in late 200

was an important prerequisite for the emergence of

podcast A podcast is a program made available in digital format for download over the Internet. For example, an episodic series of digital audio or video files that a user can download to a personal device to listen to at a time of their choosing ...

ing, perhaps the most common use of the feature . In podcasts and related technologies enclosures are not merely attachments to entries, but provide the main content of a feed.

Syntax

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

of a file, ''length'' is its size in

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

s, and ''type'' its

mime type A media type (also known as a MIME type) is a two-part identifier for file formats and format contents transmitted on the Internet. The Internet Assigned Numbers Authority (IANA) is the official authority for the standardization and publication o ...

. It is recommended that only one element is included per .

Prefetching

The RSS <enclosure> has similarities to: * the SMIL <prefetch> element, * the

HTML The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

Link header with rel="prefetch". (See section 19.6.2.4.) * the

Atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas ...

References

External links

The tag in the RSS 2.0 specification

- Enclosures in RSS 1.x RSS Web syndication formats XML-based standards {{Podcasting-stub

Syntax

Prefetching

See also

References

External links