17 C.F.R. § 240.12b-15
All amendments must be filed under cover of the form amended, marked with the letter "A" to designate the document as an amendment, e.g., "10-K/A," and in compliance with pertinent requirements applicable to statements and reports. Amendments filed pursuant to this section must set forth the complete text of each item as amended. Amendments must be numbered sequentially and be filed separately for each statement or report amended. Amendments to a statement may be filed either before or after registration becomes effective. Amendments must be signed on behalf of the registrant by a duly authorized representative of the registrant. An amendment to any report required to include the certifications as specified in § 240.13a-14(a) or § 240.15d-14(a) must include new certifications by each principal executive and principal financial officer of the registrant, and an amendment to any report required to be accompanied by the certifications as specified in § 240.13a-14(b) or § 240.15d-14(b) must be accompanied by new certifications by each principal executive and principal financial officer of the registrant. An amendment to any report required to include the certifications as specified in § 240.13a-14(d) or § 240.15d-14(d) must include a new certification by an individual specified in § 240.13a-14(e) or § 240.15d-14(e) , as applicable. The requirements of the form being amended will govern the number of copies to be filed in connection with a paper format amendment. Electronic filers satisfy the provisions dictating the number of copies by filing one copy of the amendment in electronic format. See § 232.309 of this chapter (Rule 309 of Regulation S-T).
17 C.F.R. §240.12b-15