(a) All operators are required by part 41 (Notification of Legal Identity) of this chapter to file with MSHA the name and address of record of the operator. All representatives of miners are required by part 40 (Representative of Miners) of this chapter to file with MSHA the mailing address of the person or organization acting in a representative capacity. Proposed penalty assessments delivered to those addresses shall constitute service.(b) If any of the parties choose to have proposed penalty assessments mailed to a different address, the Office of Assessments must be notified in writing of the new address. Delivery to this address shall also constitute service.(c) Service for operators who fail to file under part 41 of this chapter will be upon the last known business address recorded with MSHA.