best practices for mixing STAC with non-STAC Collections

[cholmes]

We should have recommendations for how people combine STAC with non-STAC data in a single landing page, with some collections being STAC and some just Features, and how clients should deal with that. Latest discussion recommends clients just look for stac_version in responses.

[philvarner]

Mixing STAC and non-STAC items seems tricky, since the clients must then constantly check the entities to validate that they're STAC. It seems like the ability to mix STAC and non-STAC objects implies:

• /collections could return non-STAC Collections (e.g., also return OAFeat Collections), and a STAC client needs to check each one for stac_version to see which type it is?
• /search or /collections/{cid}/items could return Features instead of Items, and the client needs to check?
• child links from the root could be either to STAC Collections or OAF Collections, and the client needs to check?

[philvarner]

Moved:

• best practices for mixing STAC with non-STAC Collections stac-api-extensions/best-practices#1