320 ILCS 25/3.11
"Rent constituting property taxes accrued" means 25% of the amount of gross rent paid in a taxable year for a residence which was subject to ad valorem property taxes in that year under the Property Tax Code.
(from Ch. 67 1/2, par. 403.11)
(Source: P.A. 87-860; 88-670, eff. 12-2-94.)