020) since January 1, 1995. By law, most sellers of real property must provide a completed Seller Disclosure Statement (aka Form 17) to any buyer.The Form 17 permits a seller to mark answers to the form questions as "Yes", "No", "I don't know", and "NA." To be used in transfers of improved residential real property, including residential dwellings up to four units, new construction,. You must fill out a Seller Disclosure Statement (also known as Form 17). You must tell the buyer any problems with the property that you know about. The current form is 6 pages long and includes most of the typical property issues requiring disclosure with a catchall question for anything left out. Nearly all real estate sales in Washington State require a seller disclosure statement, also known as Form 17, to be given to the buyer. Hey Buddy Buck here! Edit, sign, and share Seller Disclosure Statement-Improved Property (Rev.