Can a flavor with no extra specs be assigned to an aggregate with metadata?

Issue

• Given an aggregate (availability zone) with metadata, and a flavor with no extra specs, can that flavor be provisioned into this aggregate?
• Can flavor VMs with no extra specs be provisioned into an aggregate, even though the flavor does not have the extra specs that match the aggregate?
• What are the instance scheduling rules around flavors and aggregates (availability zones)?
• Where can I find more information on nova-scheduler filter logic?