A mobile home park rule that does either of the following shall not be enforced against a resident, unless the rule was proposed and in force before the resident was approved for tenancy in the mobile home park:

    (a) Prohibits those children who were previously approved under prior park rules from residing in the mobile home park. A rule prohibiting children, or additional children, shall not be enforced against persons who were residents of the mobile home park at the time the rule was adopted until after 1 year's notice to those persons.

    (b) Prohibits a resident from keeping those pets which were previously approved under prior park rules, except dangerous animals.