20 Requirement for policy documents to be publicly available
(1) An agency must make copies of each of its policy documents available for inspection and purchase by the public.
(2) However, nothing in this section prevents an agency from deleting exempt information or contrary to public interest information from a copy of a policy document.
(3) A person must not be subjected to any prejudice because of the application of the provisions of an agency's policy document (other than provisions the agency is permitted to delete from a copy of the document) to any act or omission of the person if, at the time of the act or omission—
(a) the policy document was not available for inspection and purchase; and
(b) the person was not aware of the provisions; and
(c) the person could lawfully have avoided the prejudice had the person been aware of the provisions.