HUD may approve a homeownership program as submitted, conditionally approve it under § 906.47(e), or return it to the PHA for revision and resubmission. Where such conditional approval is given, the PHA, partners, and contractors remain subject to the restrictions in § 906.47. Upon HUD notification to the PHA that the homeownership program is approvable (in final form that satisfies all applicable requirements of this part), the PHA and HUD will execute a written implementing agreement, in a form prescribed by HUD, to evidence HUD approval and authorization for implementation. The program itself, as approved by HUD, must be incorporated in the implementing agreement. Any of the items of supporting documentation may also be incorporated, if agreeable to the PHA and HUD. The PHA is obligated to carry out the approved homeownership program and other provisions of the implementing agreement without modification, except with written approval by HUD.