49 CFR § 386.35 - Motions to dismiss and motions for a more definite statement.
(a) Motions to dismiss must be made within the time set for reply or petition to review, except motions to dismiss for lack of jurisdiction, which may be made at any time.
(b) Motions for a more definite statement may be made in lieu of a reply. The motion must point out the defects complained of and the details desired. If the motion is granted, the pleading complained of must be remedied within 15 days of the granting of the motion or it will be stricken. If the motion is denied, the party who requested the more definite statement must file his/her pleading within 10 days after the denial.