N.H. Rev. Stat. § 472:4
A writing, reciting that the parties signing the same are adjoining owners, that the division line between their lands is in dispute, that the line described in their respective deeds or in the deeds of any of their predecessors in title cannot be located on the ground by reason of the loss or obliteration of the monuments and boundaries therein named and described, and containing a full and complete description of the line thus agreed upon and established, and the volume and page where their said respective deeds are recorded, or if title was not acquired by deed, a statement identifying each owner's other source of title, shall be signed and acknowledged by the parties to the agreement before any officer having authority to take the acknowledgment of deeds, and recorded with the registry of deeds for the county where the lands are located, and, when the volume and page of an owner's deed is set forth in said agreement, the register of deeds shall note the recording of said agreement on the margin where the said respective deeds of the parties to said agreement are recorded. In those registries recording on microfilm, in lieu of noting the recording of said agreement on the margin where the respective deeds of the parties to said agreement are recorded, the register of deeds shall list all parties to the agreement in both the grantor and grantee indices.
RSA 472:4
1903, 48:2. PL 219 :29. RL 269:29. RSA 472:4. 1963, 173:1. 1977, 283:1. 1988, 85:1, eff. Jan. 1, 1989.