; or (3) to refer to or place an alien in removal proceedings pursuant to section 240, or in any other proceedings, if such referral is not otherwise authorized under this Act. (c) Transition rules (1) Mandatory processing Beginning on the date that is 90 days after the date of the enactment of this section, the Secretary shall require any alien described in subsection (a) who does not meet any of the criteria described in paragraphs (1) through (6) of that subsection to be processed in accordance with section 235 or 235B, as applicable, unless such alien is subject to removal proceedings under subsection (b)(3). (2) Pre-certification referrals and placements Before the Comptroller General of the United States has certified that sections 235B and 240D are fully operational pursuant to section 146(d) of the Border Act , the Secretary shall refer or place aliens described in subsection (a) in proceedings under section 240 based upon operational considerations regarding the capacity of the Secretary to process aliens under section 235 or section 235B, as applicable. (3) Post-certification referrals and placements After the Comptroller General makes the certification referred to in paragraph (2), the Secretary may only refer aliens described in subsection (a) to, or place such aliens in, proceedings under section 235(b) or 235B, as applicable, unless such alien is subject to removal proceedings under subsection (b)(3). . (2) Clerical amendment The table of contents of the Immigration and Nationality Act ( 8 U.S.C. 1101 et seq. ) is amended by inserting after the item relating to section 244 the following: Sec. 244A. Special rules for contiguous continental land borders. . (b) Modification of authority to arrest, detain, and release aliens (1) In general Section 236(a)(2) of the Immigration and Nationality Act ( 8 U.S.C. 1226(a)(2) ) is amended— (A) in the matter preceding subparagraph (A), by striking on ; (B) in subparagraph (A), by inserting on before bond