Indiana Code Title 14. Natural and Cultural Resources § 14-33-2-3

(1) Only one (1) freeholder's signature may be counted for any one (1) freehold.  If a freehold is held in joint title, only one (1) freeholder's signature may be counted and it may be the signature of any one (1) of the freeholders owning the freehold in joint title.  If a given freeholder qualifies as set forth in this section for at least two (2) freeholds, the freeholder's signature shall be counted for each freehold.

(2) One (1) or more tracts of land owned solely by only one (1) freeholder constitute one (1) freehold.

(3) One (1) or more tracts of land owned in joint title by at least two (2) identical freeholders constitute one (1) freehold.  However, if one (1) of the freeholders owning the freehold in joint title is a different or additional person, each freehold in joint title among nonidentical persons constitutes a separate and additional freehold.

(4) Subject to subdivisions (1), (2), and (3), if:

each freeholder in the area of the municipality that is in the proposed district is counted as a signatory to the petition.  However, if a freeholder in the area of the municipality that is in the proposed district, after the filing of the petition for the establishment of the district, files a petition against the establishment of the proposed district, the number of freeholders considered and counted as signatories to the petition must be reduced by the number of freeholders in the area of the city that is in the proposed district filing a petition against the establishment of the district.

(5) Private corporations owning land in the proposed district may sign the petition by any officer authorized by the corporation.  The officer's signature is prima facie evidence of the officer's authorization to sign the petition.