Empty, clean and with an active census reservation. Legacy appointment links do not count. Never matches an occupied kennel or a dirty, storage or do not use one.
Stored physical status is clean, occupied or not. Leaves out `RESERVED` kennels, so an empty clean kennel with an active census reservation matches `RESERVED` and not `CLEAN`.
Stored physical status is dirty, occupied or not.
Stored physical status is do not use, occupied or not.
Holds at least one patient, booked or not.
Stored physical status is storage, occupied or not.
Holds no patient. The exact complement of `OCCUPIED`; a booking does not change it.