A purchase and sale agreement or any extension of a purchase and sale agreement may be accepted for registration if the agreement or extension is acknowledged by the parties agreeing to sell or one of them.
If it is contended that a registered purchase and sale agreement is no longer in force and effect, whether by operation of G.L. c. 184, § 17A or otherwise, the court should be consulted as to any action necessary to establish that fact of record; provided, that a release executed by the person or persons identified as the buyer in the purchase and sale agreement may, without notice to the court, be accepted for registration.