There are many words and phrases used when talking about Atom, syndication and aggregation. This page tries to sort out what these words and phrases mean.

Notes for wiki editors:

Things specifically about syndication

Aggregator, Feed reader, News reader

A reading client that works on the principle of displaying new entries when they appear, as from a feed, sometimes holding "old" entries for perusal, and re-showing updated entries if they're changed. Note: depending on context, a news reader may be referring to a Usenet news reader.

Authoring client

See editing client.

Blog, Weblog

A frequently-updated style of homepage on the web, characterised by short items displayed in reverse chronological order.


A property of an entry, or a resource within a site, that groups other resources sharing a common attribute (adapted from [WWW]wordnet), in contrast to a section of a site. In Atom -00, it is common for a category to have its own feed.


A program that establishes connections for the purpose of sending requests. ([WWW]RFC2616) Atom clients initiate requests for Atom resources, such as feed and entry resources, and resources linked from those resources. Atom clients make use of the Atom Publishing protocol. In HTTP terms, an Atom client is a user agent, "The client which initiates a request.".


An entry resource that is a response, as in a conversation, to an entry, comment, or other resource, in contrast to an annotation, citation, or side reference. In Atom -00, an entry resource is considered a comment resource if it appears in a feed associated directly with a specific entry resource, in which each comment is considered a response to the specific entry (even if, within the context of the replies, it is a comment on another comment). PaceLinkParent is a proposal to explicitly identify comment resources by including a "parent" or "in-reply-to" link that references the resource being replied to, also allowing a comment to be in response to another comment, particularly.


See client.

Editing client

A client for maintaining resources on a publishing system. An Atom editing client uses the Atom protocol editing (particularly non-feed) endpoints. Synonym: authoring client.


A principal published resource that is part of a set or series, such as would appear in a front page "news", a digest, hierarchical sitemap or index, or news box. In Atom -00 an entry is represented as an <atom:entry> element, which includes metadata element children. The resource representation might exist as a document element in a separate XML document, or as a child node of <atom:feed>. What separates an entry from non-text entry is that an entry representation in Atom -00 contains the "body content" information within the representation and the non-text entry references another resource by its URI.

Entry-related resource

A resource that is grouped with the entry and referenced by URI, but is not a non-text entry. An entry-related resource might be photos, diagrams, equations, audio clips, etc. referenced from an entry (root) resource that provides context for them. Entry-related resources can be shared among entry resources. Entry and non-text entry resources may also be entry-related resources of another entry resource.


A resource updated over a time interval containing or listing other resources. In Atom -00, only entry resources are considered significant for inclusion in feeds. In Atom -00 a feed is represented as an <atom:feed> element (document type) which includes metadata element children describing the feed and a set of atom:entry elements.

Feed reader

See aggregator.


A resource listing other resources, potentially spanning multiple index resources organized in some fashion. In Atom, an index is a proposed use of the atom:feed element, which in Atom -00 would only consist of entry resources.


An aggregator and feed producer that fetches feeds from multiple sources, selects entries for republication, and publishes new feeds containing entries from the various sources; for example a news searching/matching service.


Traditionally, metadata has been understood as "data about data"; for example, a library catalog contains information (metadata) about publications (data) ([WWW]source). In some formats, metadata is often held in message headers that accompany a message body. In Atom, atom:feed and atom:elements intermix metadata (header elements) and body (atom:entry elements in a feed, and atom:content element in an entry). In some cases [proposed], an Atom entry is the metadata record for a resource stored at a separate URI.

Metadata record

A set (subset) of data held separate from the data it is derived, culled, or pulled from.


(1) A small resource, either standalone or as properties on another resource. Examples include reviews, playlists, entries, Foaf, iCalendar, and vCard. (2) Content that conveys one primary idea or concept, is accessible through a single definitive URL or permalink, and is appropriately written and formatted for presentation in email clients, web browsers, or on handheld devices as needed. Examples include a day's weather forcast, the arrival and departure times for an airplane flight, an abstract from a long publication, or a single instant message. ([WWW]source)

News reader

See aggregator.

Non-entry resource

A resource available on a site that is not typically grouped with an entry, such as templates, stylesheets, documents, multimedia, downloads (ZIP, TAR), configuration, etc.

Non-text entry

An entry whose main "body content" is not one of the common textual formats (X/HTML, plain text). In Atom -00 a non-text entry has its metadata in an <atom:entry> element and the "body content" resource is referenced by URI.


See publishing system.

Publishing process

The order and discipline used by humans in using a publishing system. Publishing processes can range from informal (little order or discipline) to highly formal (significant order and discipline). This can affect the quality or scope of resources published. Atom -00 generally contains information useful in the lowest common form (informal) and expects extensions to carry information (such as workflow, status, or significance of change/modification) in extensions.

Publishing system

An application that manages, controls, and makes accessible the resources edited and read by clients. An Atom publishing system makes use of the Atom publishing format and protocol. An Atom publishing system may make use of a "static" web server to serve much or all of its output resources.


See consumer.

Reading client

A client that organizes and displays published information from a publishing system. An Atom reading client uses the Atom protocol feed and possibly introspection endpoints.


Anything that has been named or described can be a resource. Familiar examples include an electronic document, an image, a service (e.g., "today's weather report for Los Angeles"), and a collection of other resources. ([WWW]RFC2396bis)


A resource within a site that is separate or distinct from others, in contrast to being a category of another resource. In Atom -00, it is common for a section, like b-links, photoblog, or playlist, to have its own feed.


A Web Resource, identified by URI, which is a collection of other Web Resources, each identified by URI. ([WWW]source) In Atom -00, one or more resources of a site may have a corresponding feed. In Atom -00 it is common for the site, or main, feed to contain all the entry resources in category feeds, but exclude entry resources in section or comment feeds.


See blog.

IDs, URIs, URNs, URLs, and Permalinks

[WWW]Uniform Resource Identifier (URI): Generic Syntax (aka RFC2396bis), an Internet Draft for replacing RFC2396 and [WWW]Architecture of the World Wide Web are excellent sources of information on URIs.

GUID, Globally unique (identifier)

An identifier that, through a global naming system or registrar, is unique at the time it is created, in contrast to a universally unique identifier, which is unique across time. Note: often the term GUID is used synonomously with UUID.


An unambiguous reference to the resource within a given context. ([WWW]Dublin Core) In Atom -00, atom:feed and atom:entry resources have an <id> URI that must never change as long as it is the "same" feed or entry.


A vague term used on the web that variously refers to the "main" URI location or any number of URI locations for the browser-viewable version of a resource. The term permalink is not used in Atom specifications.


A Uniform Resource Identifier (URI) is a compact sequence of characters for identifying an abstract or physical resource. ([WWW]RFC2396bis) In Atom -00, URIs are used for <id>s and a variety of link relationships.

URI Location

A phrase used to indicate that a given URI is a URI locator and intended to be resolved by its primary access mechanism.

URI Resolution

URI "resolution" is the process of determining an access mechanism and the appropriate parameters necessary to dereference a URI; such resolution may require several iterations. To use that access mechanism to perform an action on the URI's resource is to "dereference" the URI. ([WWW]RFC2396bis) In Atom -00, some link types are resolvable using the URI scheme as the primary access mechanism; other link types, such as often promoted for <id> and <link rel="in-reply-to" href=",2004:/blog/kitty"> require a secondary access mechanism, such as an internal cache of entries and feeds, or a service that will resolve a URI name to one or more URI locations for that URI.

URL, URI locator

The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network "location"). ([WWW]RFC2396bis)

URN, URI name

The term "Uniform Resource Name" (URN) has been used historically to refer to both URIs under the "urn" scheme [RFC2141], which are required to remain globally unique and persistent even when the resource ceases to exist or becomes unavailable, and to any other URI with the properties of a name. ([WWW]RFC2396bis)

UUID, Universally unique (identifier)

An identifier that is unique across all time, by use of data/time in addition to any other global naming system or registration, in contrast to a globally unique identifier which is only known to be unique when it is created.

Other stuff


The word pace is used as a prefix for all issues we need to focus and and have a steady pace (speed) on. It indicates that the given issue is important, but also not a too major change of the current specification. An issue of changing a couple of words in the specification is a typical pace, while wanting Atom to be serialized in comma separated values instead of XML is not.