(a) If the lands applied for lie within and conform to the rectangular system of public land surveys and constitute either all or a portion of the tract acquired by the United States, such lands shall be described by legal subdivision, section, township, range, and, if needed, meridian.

(b) If the lands applied for do not conform to the rectangular system of public land surveys, but lie within an area of the public land surveys and constitute the entire tract acquired by the United States, such lands shall be described by metes and bounds, giving courses and distances between the successive angle points with appropriate ties to the nearest official survey corner, or a copy of the deed or other conveyance document by which the United States acquired title to the lands may be attached to the offer and referred to therein in lieu of redescribing the lands on the offer form. If the desired lands constitute less than the entire tract acquired by the United States, such lands shall be described by metes and bounds, giving courses and distances between the successive angle points with appropriate ties to the nearest official survey corner. If a portion of the boundary of the desired lands coincides with the boundary in the deed or other conveyance document, that boundary need not be redescribed on the offer form, provided that a copy of the deed or other conveyance document upon which the coinciding description is clearly identified is attached to the offer. That portion of the description not coinciding shall be tied by description on the offer by courses and distances between successive angle points into the description in the deed or other conveyance document.

(c) If the lands applied for lie outside an area of the public land surveys and constitute the entire tract acquired by the United States, such lands shall be described as in the deed or other conveyance document by which the United States acquired title to the lands, or a copy of that document may be attached to the offer and referred to therein in lieu of redescribing the lands on the offer form. If the desired lands constitute less than the entire tract acquired by the United States, such lands shall be described by courses and distances between successive angle points tying by courses and distances into the description in the deed or other conveyance document. If a portion of the boundary of the desired lands coincides with the boundary in the deed or other conveyance document, that boundary need not be redescribed on the offer form, provided that a copy of the deed or other conveyance document upon which the coinciding description is clearly identified is attached to the offer. That portion of the description not coinciding shall be tied by description in the offer by courses and distances between successive angle points into the description in the deed or other conveyance document.

(d) Where the acquiring agency has assigned an acquisition or tract number covering the lands applied for, without loss of priority to the offeror, the authorized officer may require that number in addition to any description otherwise required by this section. If the authorized officer determines that the acquisition or tract number, together with identification of the State and county, constitutes an adequate description, the authorized officer may allow the description in this manner in lieu of other descriptions required by this section.

(e) Where the lands applied for do not conform to the rectangular system of public land surveys, without loss of priority to the offeror, the authorized officer may require 3 copies of a map upon which the location of the desired lands are clearly marked with respect to the administrative unit or project of which they are a part.