HTML and CSS Reference
The entry elements without content must provide a minimum of one link element with the rel attribute and
the alternate attribute value.
The entry elements cannot contain more than one link element with the rel attribute and the alternate
attribute value with exactly the same type and hreflang attribute values. Optionally, additional link elements can
also be provided for the entry elements.
The entry elements can contain a maximum of one published , rights , source , and summary element.
The summary subelement should be provided for entry elements if the entry contains a content element with the
src attribute or the entry content is Base64 encoded. 1
The entry elements must contain exactly one title and one updated element.
The content Element
The Atom news content can be provided by the content element. The content of this element is language-sensitive.
The content element has two attributes: type and src .
The value of the type attribute on the content element might be text , html , or xhtml . If it is omitted, text
is considered the default value by Atom readers. Another option is to provide a MIME media type (but not a
The content element has an optional src attribute. The value of this attribute should be an Internationalized
Resource Identifier that conforms to RFC 3987. If the src attribute is provided, the content must be empty. The type
attribute should also be provided with a MIME type along with the src attribute.
Metadata and Content Elements
Similar to RSS, there are several elements in Atom to express metadata and describe the contents of news entries, such
as author , category , contributor , generator , icon , id , link , logo , published , rights , source , subtitle , summary ,
title , and updated . Those elements whose specification assigns meaning to the content and the ones with special
restrictions are described in the following sections.
The author Element
The author in Atom feeds can be provided in three levels. If the author element is not provided as a subelement of
an entry element, the author is derived from the author subelement of the source element. Otherwise, the author
declared by the author of the feed element is used to display the author of the news (Listing 8-36).
Listing 8-36. Declaring the Author of an Atom Feed
The category Element
The category element has three attributes: the required term and the optional scheme and label (Listing 8-37).
1 Although the type attribute of the atom:content element is an Internet media type, it neither is an XML media type nor begins
with text/ or ends in /xml or +xml .