(a) This section does not apply to an affordable housing land trust agreement executed under Title 14, Subtitle 5 of this article.

(b) This section is effective on July 1, 1969, with respect to (1) inter vivos instruments taking effect on or after that date, (2) wills of persons who die on or after that date, and (3) appointments by inter vivos instruments or wills made on or after that date under powers created before that date.

(c) If the specified contingency of a special limitation creating a possibility of reverter or of a condition subsequent creating a right of entry for condition broken does not occur within 30 years of the effective date of the instrument creating the possibility or condition, the possibility or condition no longer is valid thereafter.