020) since January 1, 1995. To be used in transfers of improved residential real property, including residential dwellings up to four units, new construction,.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. Hey Buddy Buck here! Learn more about the NWMLS Form 17 (or Seller Disclosure Statement). Almost all sellers in WA must complete and provide one to a buyer. 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. Nearly all real estate sales in Washington State require a seller disclosure statement, also known as Form 17, to be given to the buyer. Nearly all real estate sales in Washington State require a seller disclosure statement, also known as Form 17, to be given to the buyer.