classified, except that such information may be disclosed to a court ex parte and in camera for purposes of judicial review under subsection (c). (4) Period of designation (A) In general A designation under this subsection shall be effective for all purposes until revoked under paragraph (5) or (6) or set aside pursuant to subsection (c). (B) Review of designation upon petition (i) In general The Secretary shall review the designation of a criminal gang under the procedures set forth in clauses (iii) and (iv) if the designated group, club, organization, or association of 5 or more persons files a petition for revocation within the petition period described in clause (ii). (ii) Petition period For purposes of clause (i)— (I) if the designated group, club, organization, or association of 5 or more persons has not previously filed a petition for revocation under this subparagraph, the petition period begins 2 years after the date on which the designation was made