5 C.F.R. § 2429.25

(a) General rule. Except as discussed in paragraph (b) of this section, and unless you use an FLRA-prescribed form, any document that you file with the Authority, General Counsel, Administrative Law Judge, Regional Director, or Hearing Officer, including any attachments, must be on 8 1/2 by 11-inch size paper, using normal margins and font sizes. You must file one original document, but you may substitute for the original document a clean copy of that document, so long as the copy is capable of being used as an original for purposes such as further reproduction.

(b) Exceptions. You are not required to comply with paragraph (a) of this section if and only if:

(1) You file documents electronically through use of the FLRA's eFiling system;

(2) The Authority or the General Counsel, or their designated representatives, allow you not to comply; or

(3) Another provision of this subchapter allows you not to comply.