Namespaces

Namespaces define extension vocabularies like content, media, and itunes.

Checked by FeedInspector

Capability checks

Metrics

hasFullContentLikely

Definition

XML namespaces map prefixes to URIs so extension tags can be interpreted correctly.

Why it matters

Without matching namespace declarations, custom tags may be ignored by clients or parsed unpredictably.

How FeedInspector checks it

FeedInspector extracts declared and used namespaces and shows tag samples for each prefix in the namespaces table.

Common problems and fixes

Problem: Prefix is used in tags but xmlns declaration is missing.
Fix: Declare each used prefix on rss, feed, or a valid parent element.
Problem: Prefix is declared but points to the wrong URI.
Fix: Use official namespace URIs for content, media, itunes, and dc.

Minimal example

Root namespace declarations

<rss
  version="2.0"
  xmlns:content="http://purl.org/rss/1.0/modules/content/"
  xmlns:media="http://search.yahoo.com/mrss/">
  <channel>
    <item>
      <content:encoded><![CDATA[<p>Body</p>]]></content:encoded>
      <media:thumbnail url="https://example.com/thumb.jpg" />
    </item>
  </channel>
</rss>