19. Engagement by a person, for remuneration, in the art or science of accountancy or in the auditing of books or accounts and the offer of his services to the public for such purposes constitutes the practice of public accountancy.
However, a person does not practise public accountancy within the meaning of this Act if he acts exclusively as a book-keeper, provided that if he offers his services to the public, he advertises only as a book-keeper.