§ 483. Signs advertising services as attorney at law. It shall be
unlawful for any person to maintain on real property or to permit or
allow any other person to maintain, on such property a sign, in any
language, to the effect that an attorney-at-law or legal services are
available therein unless the full name of the attorney-at-law or the
firm rendering such services is set forth thereon. In any prosecution
for violation of the provisions of this section the existence of such a
sign on real property shall be presumptive evidence that it was placed
or permitted to exist thereon with the knowledge and consent of the
person or persons in possession of said premises.