Requirements for content in the feed are the same, regardless of the [Feed format](🔗).
The pre-defined RSS-elements allow only for limited details about a product or item.
To include more information about a product or item in your catalog, the RSS 2.0 format is extended by adding custom elements defined in the Optimizely Personalization (Recommendations) namespace. These elements are prefixed with `
[Mandatory channel elements](🔗)
[Mandatory item elements](🔗)
[Optional item elements](🔗)
See each topic for details. See [RSS 2.0 feed sample](🔗) for an example of a product feed.