Section 27. No restriction imposed after December thirty-first, nineteen hundred and sixty-one shall be enforceable:—

(a) unless the person seeking enforcement (1) is a party to the instrument imposing the restriction and it is stated to be for his benefit or is entitled to such benefit as a successor to such party, or (2) is an owner of an interest in benefited land which either adjoins the subject parcel at the time enforcement is sought or is described in the instrument imposing the restriction and is stated therein to be benefited, and

(b) after thirty years from the imposition of the restriction, unless (1) the restriction is imposed as part of a common scheme applicable to four or more parcels contiguous except for any intervening streets or ways, and provision is made in the instrument or instruments imposing it for extension for further periods of not more than twenty years at a time by owners of record, at the time of recording of the extension, of fifty per cent or more of the restricted area in which the subject parcel is located, and an extension in accordance with such provision is recorded before the expiration of the thirty years or earlier date of termination specified in the instrument and names or is signed by one or more of the persons appearing of record to own the subject parcel at the time of such recording, and in case of such recording, twenty years, or the specified extension term if less than twenty years, has not expired after the recording of any such extension without the recording of a further like extension; or (2) in the case of any other restriction, a notice of restriction is recorded before the expiration of the thirty years, and in case of such recording, twenty years have not expired after the recording of any notice of restriction without the recording of a further notice of restriction.

A notice of restriction under this section shall not extend the period of enforceability unless it (a) is signed by a person then entitled of record to the benefit of the restriction and describes his benefited land, if any, (b) describes the subject parcel, (c) names one or more of the persons appearing of record to own the subject parcel at the time, and (d) specifies the instrument imposing the restriction and its place of record in the public records.