Documents 43 C.F.R. § 4.401

          (a) Grace period for filing. Whenever a document is required under this subpart to be filed within a certain time and it is not received in the proper office during that time, the delay in filing will be waived if the document is filed not later than 10 days after it was required to be filed and it is determined that the document was transmitted or probably transmitted to the office in which the filing is required before the end of the period in which it was required to be filed. Determinations under this paragraph shall be made by the officer before whom is pending the appeal in connection with which the document is required to be filed.

          (b) Transferees and encumbrancers. Transferees and encumbrancers of land the title to which is claimed or is in the process of acquisition under any public land law shall, upon filing notice of the transfer or encumbrance in the proper land office, become entitled to receive and be given the same notice of any appeal, or other proceeding thereafter initiated affecting such interest which is required to be given to a party to the proceeding. Every such notice of a transfer or encumbrance will be noted upon the records of the land office. Thereafter such transferee or encumbrancer must be made a party to any proceedings thereafter initiated adverse to the entry.

          (c) Service of documents.

                    (1) Wherever the regulations in this subpart require that a copy of a document be served upon a person, service may be made by delivering the copy personally to him or by sending the document by registered or certified mail, return receipt requested, to his address of record in the Bureau.

                    (2) In any case service may be proved by an acknowledgment of service signed by the person to be served. Personal service may be proved by a written statement of the person who made such service. Service by registered or certified mail may be proved by a post-office return receipt showing that the document was delivered at the person’s record address or showing that the document could not be delivered to such person at his record address because he had moved therefrom without leaving a forwarding address or because delivery was refused at that address or because no such address exists. Proof of service of a copy of a document should be filed in the same office in which the document is filed except that proof of service of a notice of appeal should be filed in the office of the officer to whom the appeal is made, if the proof of service is filed later than the notice of appeal.

                    (3) A document will be considered to have been served at the time of personal service, of delivery of a registered or certified letter, or of the return by post office of an undelivered registered or certified letter.