49 CFR 1104.3: Paper filings, electronic submissions, and copies.

(a) The executed original of a paper pleading or document permitted or required to be filed under this subchapter, including correspondence, must be furnished for the use of the Board. Textual submissions of 20 or more pages must be accompanied by an electronic version. Details regarding electronic submissions, including evidence, workpapers, and other pertinent information are available on the Board's website, www.stb.gov.

(b) The Board may, at its discretion, request paper copies of a pleading, document, or paper filed or e-filed with the Board. Any such copies must be clear and legible. Appropriate notes or other indications shall be used so that matters shown in color on the original, but in black and white on copies, will be accurately identified on all copies.