Following up on the comments at [1], provide further disambiguation and clarity on the difference between placement aggregates and nova host aggregates, with some illustrative examples that include where the former may be used to represent the latter (as is being proposed via [2]). [1] https://review.openstack.org/#/c/539033/1/placement-api-ref/source/aggregates.inc@14 [2] https://review.openstack.org/#/q/bp/placement-mirror-host-aggregates Change-Id: I53588fca311992f885c4157591232a864b6a86b1