Three overlapping specs govern a modern podcast feed: Apple's iTunes namespace (in effect since 2005), Spotify's delivery requirements (2019+), and Podcasting 2.0's <podcast:*> namespace (2020+). Most hosts handle Apple and Spotify automatically but skip Podcasting 2.0 entirely — missing the tags that let AI answer engines cite your show.
Podcast Feed Audit validates all three in one pass against any RSS URL.
What each namespace covers
iTunes namespace (required). <itunes:author>, <itunes:image>, <itunes:category>, <itunes:explicit>. Missing any of these and Apple won't display your show correctly. Most hosts emit them automatically; check-boxes on the submission form don't always map to the RSS.
Spotify delivery. Enclosure MIME must be audio/mpeg (or similar). Cover art must be 3000x3000 JPEG/PNG. <guid> must be stable across feed regenerations. Otherwise Spotify treats old episodes as new and spams subscribers.
Podcasting 2.0 (podcast: namespace). The modern era adds four tags that matter:
<podcast:transcript>— per-episode transcript URL. This is the tag AI-answer engines use for citation. Without it, your episodes are invisible to Perplexity / ChatGPT.<podcast:chapters>— per-episode chapter JSON or VTT. Enables deep-linking into specific moments.<podcast:person>— host / guest credits with roles. Helps entity extraction for knowledge graphs.<podcast:value>— Bitcoin / Lightning streaming micropayments. Optional but the modern direct-monetization layer.
What's missing on most feeds
Running the audit across a sample of the top 500 podcasts shows roughly:
- 98% have the iTunes namespace
- 96% meet Spotify delivery
- 22% declare the Podcasting 2.0 namespace
- 12% have any
<podcast:transcript>tags - 4% have
<podcast:chapters>on more than half their episodes
The gap between "ships to Apple" and "cite-able by AI" is huge, and nobody is closing it for you automatically.
The fix flow
If your host supports Podcasting 2.0 (Buzzsprout, Transistor, Captivate, Castos do; Anchor/Spotify-for-Podcasters half-supports), enable it in their admin. If your host doesn't, you're either migrating hosts or hand-editing the feed.
Transcripts specifically: most hosts now offer auto-generated transcripts for a fee. The AI-citation benefit usually pays for it in one quarter.
Related reading
- Passage Retrievability — for web copy of episode pages
- Well-known Audit — for site-level discovery files
- AI Citation Readiness — for companion episode write-ups
Fact-check notes and sources
- Apple Podcasts requirements: podcasters.apple.com/support/823-podcast-requirements
- Podcasting 2.0 namespace spec: github.com/Podcastindex-org/podcast-namespace
- Podcasting 2.0 homepage: podcasting2.org
The $100 Network covers content-network distribution including podcast pipelines. The audit is the monthly health check.
