The following words and phrases when used in this act shall have the meanings given to them in this section unless the context clearly indicates otherwise:

“Commission.” The Pennsylvania Historical and Museum Commission of the Commonwealth.

“County.” Any county of the second through eighth class, including any of such counties as may have adopted a home rule charter.

“County records.” Any papers, dockets, books, maps, photographs or other documentary materials, regardless of physical form or characteristics, made or received in any office of county government in pursuance of law or in connection with transactions of public business in the exercise of its legitimate functions and the discharge of its responsibilities.