49 CFR § 389.21
Contents of written comments
November 18, 2020
All written comments must be in English. Any interested person must submit as part of his/her written comments all material that he/she considers relevant to any statement of fact made by him/her. Incorporation of material by reference is to be avoided. However, if such incorporation is necessary, the incorporated material shall be identified with respect to document and page.
[80 FR 59073, Oct. 1, 2015]