09-137-29 Me. Code R. § 03
The Commissioner of Inland Fisheries and Wildlife shall designate a subcategory of species identified as being of special concern that are classified as rare and may be used for advisory recommendations to other entities or agencies on fish and wildlife matters in accordance with applicable laws or rules.
Rare species shall be those Special Concern species that are dependent on specific habitat types or limited breeding locations known to be particularly vulnerable to loss or disturbance; a species that is geographically limited (e.g. < 10 sites in the state); a species identified as vulnerable (NatureServe G3 or higher, IUCN VU or higher); a species highly vulnerable to climate change; or that qualifies for MESA status, but has not yet been listed.
09-137 C.M.R. ch. 29, § 03