It depends on whether you have a sales transaction or a lease transaction.
The form titled Addendum for Seller's Disclosure of Information on Lead-Based Paint and Lead-Based Paint Hazards (TAR 1906, TREC OP-L) is a TREC form that complies with federal law. Use this form any time a TREC or TAR contract form is used in the sale of a property with a dwelling built before 1978.
The form titled Addendum Regarding Lead-Based Paint (TAR 2008) is a TAR form that complies with federal law. Texas REALTORS® should use this form when the TAR Residential Lease form is used for residential property built before 1978. This form is for lease transactions only.