This exclusion (PDF) is for homeowners aged 65 or older or those totally and permanently disabled as of January 1. If you are applying you must fall into the following categories:
Joint owners (other than husband and wife) who meet all other requirements may be eligible for a partial exemption not to exceed their proportionate share of the valuation of the property.
The Social Security number information is mandatory and will be used to establish the identification of the applicant, 42 U.S.C. Section 405(c)(2)(C)(i).