30 MAC Pt. 1, R. 6.5.3

It shall be a violation of these rules for a CPA or firm permit holder to persist in contacting a prospective client when the prospective client has made known or the CPA or firm permit holder should have known the prospective client's desire not to be contacted. Any attempt to continue a contact, which the CPA or firm permit holder knows or should know is unwanted, is not permitted.