Ind. Code § 32-29-10-1

Sec. 1. As used in this chapter, "series mortgage" means any mortgage, indenture of trust, or trust deed executed to create a lien on any property, whether real or personal or both, in Indiana to secure one (1) or more series of bonds, notes, or debentures. The term applies without regard to whether the total obligation to be secured is specifically defined, limited, or left open in the original security instrument.