49 C.F.R. § 40.371
On what information does an initiating official rely in deciding whether to start a PIE proceeding?
(a) An initiating official may rely on credible information from any source as the basis for starting a PIE proceeding.
(b) Before sending a correction notice (see § 40.373), the initiating official informally contacts the service agent to determine if there is any information that may affect the initiating official's determination about whether it is necessary to send a correction notice. The initiating official may take any information resulting from this contact into account in determining whether to proceed under this subpart.