(1) A release of part of land from -
(a) a rentcharge does not extinguish the rentcharge, but bars only the right to recover any part of the rentcharge out of the land released,
(b) a judgment charged on the land does not affect the validity of the judgment as regards any of the land not specifically released.
(2) Subsection (1) does not -
(a) prejudice the rights of any person interested in the land unreleased and not concurring in or confirming the release, or
(b) prevent recovery of the whole of the rentcharge or enforcement of the whole judgment against the land unreleased, unless those interested agree otherwise.