Section 12-8-400.1 - DEFINITION OF TERMS USED IN THIS SECTION(1)ADA - Americans with Disabilities Act (2)Escalation - the right of a Lessor to assess Lessee for all or a portion of increases in Lessor's costs over the term of the Lease, such as increased utility, property tax or insurance costs. (3)Estoppel Certificate - a written certificate in which a tenant sets forth the condition of the lease agreement at the time of certification, any modifications made to the Lease, and whether any promises made by Lessor have yet to be fulfilled. Required by potential buyers or mortgages of property, as assurance that the Leases held by Lessor are valid and without offsets or claims pending. (4)Expense Stop - the right of a Lessor to pay operating costs up to a certain stipulated amount or amount per square foot, with Lessee paying any amount in excess of this amount. (5)HVAC - Heating, ventilation and air-conditioning system. (6)Substitution of Premises - the right of a Lessor to relocate the tenant to comparable space in a multi-tenant building during the Lease term. (7)Tenantable - habitable, in a condition suitable for a tenant. 12 Miss. Code. R. 8-400.1