Section 217.117 - [Effective 5/18/2028] Letters of Authorization(a) A Letter of Authorization, unless suspended or revoked, will be valid for a period of time not to exceed the period of validity of this subpart.(b) Each Letter of Authorization will set forth:(1) Permissible methods of incidental taking;(2) Means of effecting the least practicable adverse impact on the species, its habitat, and on the availability of the species for subsistence uses; and(3) Requirements for monitoring and reporting.(c) Issuance and renewal of the Letter of Authorization will be based on a determination that the total number of marine mammals taken by the activity as a whole will have no more than a negligible impact on the species or stock of affected marine mammals. 88 FR 31654 , 5/18/2023through 5/18/2028