49 C.F.R. § 1122.3
The Board staff may, in its discretion, conduct nonpublic Preliminary Fact-Finding, subject to the provisions of §1122.6, to determine if a matter presents an alleged violation that could be of national or regional significance and subject to the Board's jurisdiction under 49 U.S.C. Subtitle IV, Part A, and warrants a Board-Initiated Investigation. Board staff shall inform the subject of Preliminary Fact-Finding that Preliminary Fact-Finding has commenced. Where it appears from Preliminary Fact-Finding that a Board-Initiated Investigation is warranted, staff shall so recommend to the Board. Where it appears from the Preliminary Fact-Finding that a Board-Initiated Investigation is not warranted, staff shall conclude its Preliminary Fact-Finding and notify any parties involved that the process has been terminated.
49 C.F.R. § 1122.3