RSS identity reference

Feed metadata map

Metadata describes a feed, locates its resources, and identifies its entries. Use each field for its intended role and preserve stable values through conversions.

Four metadata roles

Identity fields answer which resource. Link fields answer where to retrieve or view it. Descriptive fields answer what it is. Time fields answer when it was published or changed. A durable implementation avoids substituting one role for another.

RSS 2.0

channel/title, link, and description describe the publication.
item/guid identifies an item; the optional attribute controls permalink interpretation.
item/link locates the public page.
pubDate describes publication time.
Namespaces add full content, media, podcast, and self-link metadata.

Atom

feed/id is the permanent feed identifier.
entry/id is the permanent entry identifier.
link rel="self" identifies the canonical feed document URL.
link rel="alternate" locates the human-facing representation.
updated communicates modification time.

JSON Feed 1.1

feed_url locates the feed; home_page_url locates the associated site.
Every item requires an id string.
url and external_url express distinct link relationships.
date_published and date_modified are not identifiers.
Attachments describe media separately from item identity.

Conversion rules

Preserve source identifiers. An RSS opaque GUID can be mapped into a stable Atom URI or JSON string. An Atom entry ID can become an RSS GUID with isPermaLink="false". Record every mapping so repeated conversions are idempotent.

Read Atom IDs and RFC 4287 and JSON Feed IDs for format-specific implementation guidance.