Used to declare a unique, global identifier for a podcast.
Podcasting is decentralized. There is no single point of registration or tracking. Also, podcasts move - a lot. This means that keeping track of which feed urls currently go with which podcasts is a real nightmare.
The podcast guid tag does for podcasts what the episode guid tag does for episodes. It assigns a globally unique ID to every podcast so that the world can know that two different feeds are actually the same thing - or not. Even if the podcast changes RSS address or name, the GUID sticks with it for the rest of its life.
This is easy to implement for both podcast hosting companies and podcast directories.
It’s supported by large podcast hosts including Buzzsprout and Castos.
The Podland RSS feed contains:
Because this GUID will never change, it means that this link:
will also always find the podcast, even though Podnews’s podcast pages use a separate, proprietary ID.