Except where the context of the regulation or of the Act of the Congress on which it is based, indicates otherwise, when used in the regulations of this chapter:

(a) Words importing the singular include and apply to the plural also;

(b) Words importing the plural include the singular;

(c) Words importing the masculine gender include the feminine as well;

(d) Words used in the present tense include the future as well as the present;

(e) The words person and whoever include corporations, companies, associations, firms, partnerships, societies, and joint stock companies, as well as individuals;

(f) Officer and authorized officer include any person authorized by law or by lawful delegation of authority to perform the duties described;

(g) Signature or subscription includes a mark when the person making the same intended it as such;

(h) Oath includes affirmation, and sworn includes affirmed;

(i) Writing includes printing and typewriting as well as holographs, and copies include all types of reproductions on paper, including photographs, multigraphs, mimeographs and manifolds;

(j) The word company or association, when used in reference to a corporation, shall be deemed to embrace the words successors and assigns of such company or association, in like manner as if these last-named words, or words of similar import, were expressed.

(a) Where the regulations in this chapter provide for communication by mail by the authorized officer, the requirement for mailing is met when the communication, addressed to the addressee at his last address of record in the appropriate office of the Bureau of Land Management, is deposited in the mail.

(b) Where the authorized officer uses the mails to send a notice or other communication to any person entitled to such a communication under the regulations of this chapter, that person will be deemed to have received the communication if it was delivered to his last address of record in the appropriate office of the Bureau of Land Management, regardless of whether it was in fact received by him. An offer of delivery which cannot be consummated at such last address of record because the addressee had moved therefrom without leaving a forwarding address or because delivery was refused or because no such address exists will meet the requirements of this section where the attempt to deliver is substantiated by post office authorities.

(a) The authority of the United States to enforce a public right or protect a public interest is not vitiated or lost by acquiescence of its officers or agents, or by their laches, neglect of duty, failure to act, or delays in the performance of their duties.

(b) The United States is not bound or estopped by the acts of its officers or agents when they enter into an arrangement or agreement to do or cause to be done what the law does not sanction or permit.

(c) Reliance upon information or opinion of any officer, agent or employee or on records maintained by land offices cannot operate to vest any right not authorized by law.

Whenever a regulation in this chapter requires a form approved or prescribed by the Director of the Bureau of Land Management, the Director may in that form require the submission of any information which he considers to be necessary for the effective administration of that regulation.