Recommendations Capability

If a feed element has this capability, it has a recommendation.

Property Name	Type	Description	Filter Group and Version	Available Version
`items`	A collection of these response bodies: Non-Entity Recommendation This response body isn’t available in version 34.0 and later. In version 34.0 and later, the Recommendation response body is used for all recommendations. Recommendation	A collection of recommendations.	Small, 32.0	32.0

Chatter REST API Developer Guide