Prior to Notice of Election: When a withdrawal request is received prior to the sending of the notice of election, the Board or its delegee shall grant the request without prejudice to the subsequent filing of a new petition by the petitioner. After sending of the Notice of Election. When a withdrawal request is received after the notice of election was sent, the Board shall grant the request, but may bar that party from refiling a petition for a period of 6 months from the grant of withdrawal.