Metadata

Information about channels and feed items is stored as metadata (information about information), arranged in a tree-like hierarchy.

 

Metadata tree A metadata entry can be one of two types:

For example, a channel's metadata might look something like the diagram to the right. There are two metadata groups, Link and Author, and everything else is a metadata value.

While each type of metadata can be used either as a value or group, in practice each is typically used as one or the other.

 

The following are usually used as metadata groups.

Metadata ID
Description
Author Feed/item author.
This will have one or more of the following child nodes: , ,
Contributor Feed/item contributor.
This will have one or more of the following child nodes: , ,
Editor Channel editor.
This will have either a or child node.
Webmaster Channel webmaster.
This will have either a or child node.
Image Channel image.
This will have a child node and optionally and/or child nodes.
Icon Channel icon.
This will have a child node.
Category Feed/item category.
This will have one or more of the following child nodes: , ,
Link A link.
This will have a child node and any of the following optional child nodes: , , , .
Comments Indicates where a feed item's comments can be found.
This metadata node is found in RSS feeds only and has a single child node.
Source States the item's source.
For RSS feeds, this will have a and/or a child node. For Atom 1.0 feeds, it will have one or more of the following child nodes: , , , , , , , , , , .

 

The following are usually used as metadata values.

Metadata ID
Description
ID Feed/item identifier.
Name Feed/item name.
Description Feed/item description.
Copyright Feed/item copyright message.
Language Feed/item language ID.
Published Feed/item published date.
Modified Feed/item modified date.
URL Specifies a URL.
Email Specifies an email address.
SkipDays Specifies which days a feed should not be updated.
This metadata is found in RSS feeds only and is a list of day numbers (where 0=Sunday).
SkipHours Specifies which hours a feed should not be updated.
This metadata is found in RSS feeds only and is a list of hour numbers (0-23).
Relation Specifies a relation type.
This is usually a child of a node and specifies the link's reltype.
MediaType Specifies a media type.
This is usually a child of a node and specifies the link's media type.
Width Specifies a width.
Height Specifies a height.
Size Specifies a size.
Length Specifies a length.