N.H. Rev. Stat. § 479:5
A mortgage or deed of trust which purports to be given in whole or in part as security for notes or bonds thereafter to be issued or other expectant future obligations and which states the nature of the obligations designed to be secured by it, the amount thereof presently to be issued, if any, and the limitations, if any, contained in the mortgage or deed of trust or in a contract referred to in the mortgage or deed of trust with respect to the total or maximum amount thereof ultimately to be issued shall become a lawful security for the same as, when and to the extent that they shall actually be issued or come into existence as valid obligations of the mortgagor.
RSA 479:5
1917, 120:1. 1925, 98:1. PL 215 :4. RL 261:4. 1953, 20:1, eff. Feb. 26, 1953.