20 C.F.R. § 655.33
(b) Notice content. The notice will:
(3) Direct the SWA to place the job order into intra- and interstate clearance as set forth in § 655.16 and to commence such clearance by:
(5) Where the occupation or industry is traditionally or customarily unionized, direct the SWA to circulate a copy of the job order to the following labor organizations: