50 CFR § 217.207 - 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, but must be renewed annually subject to annual renewal conditions in § 217.208.
(b) Each Letter of Authorization will set forth:
(1) Permissible methods of incidental taking; and
(2) Requirements for mitigation, monitoring and reporting, including, but not limited to, means of effecting the least practicable adverse impact on the species, its habitat, and on the availability of the species for subsistence uses.
(c) Issuance of a Letter of Authorization will be based on the determination that the number of marine mammals taken during the period the Letter of Authorization is valid will be small, that the total taking of marine mammals by the activities specified in § 217.200(a) will have no more than a negligible impact on the species or stock of affected marine mammal(s), and that the total taking will not have an unmitigable adverse impact on the availability of species or stocks of marine mammals for subsistence uses.
(d) Notice of issuance or denial of an application for a Letter of Authorization will be published in the Federal Register within 30 days of a determination.