; and (B) the class of airspace and any restrictions related to operating near airports or heliports. (2) Publication In carrying out paragraph (1), the Administrator shall ensure that published information is made available in a manner that prevents inappropriate disclosure of proprietary information. (e) Precedential use of previously approved waivers (1) Waiver approval precedent If the Administrator determines, using criteria for a particular waiver, that an application for a certificate of waiver issued under section 107.200 of title 14, Code of Federal Regulations, is substantially similar (or is comprised of elements that are substantially similar) to an application for a certificate of waiver that the Administrator has previously approved, the Administrator may streamline, as appropriate, the approval of applications for such a particular waiver. (2) Rule of construction Nothing in paragraph (1) shall be construed to preclude an applicant for a certificate of waiver from applying to modify a condition or remove a limitation of such certificate. (f) Modification of waivers (1) In general The Administrator shall establish an expedited review process for a request to modify or renew certificates of waiver previously issued under section 107.200 of title 14, Code of Federal Regulations, as appropriate. (2) Use of review process The review process established under paragraph (1) shall be used to modify or renew certificates of waiver that cover operations that are substantially similar in all material facts to operations covered under a previously issued certificate of waiver. 909. Environmental review and noise certification (a) National Environmental Policy Act guidance Not later than 180 days after the date of enactment of this Act, the Administrator shall publish unmanned aircraft system-specific environmental review guidance and implementation procedures and, thereafter, revise such guidance and procedures as appropriate to carry out the requirements of this section. (b) Prioritization The guidance and