Pursuant to the regulations in § 1.4(b) of this title, APHIS will maintain and make available for public inspection and copying a current index providing identifying information regarding the materials required to be published or made available under the Freedom of Information Act (5 U.S.C. § 552(a)(2)). Notice is hereby given that publication of this index is unnecessary and impracticable, since the material is voluminous and does not change often enough to justify the expense of publication.