A valid prescription shall be: Valid in the professional judgment of the pharmacist responsible for filling the prescription; and Conveyed: In a manner that contains the handwritten, pen-to-paper signature of the prescriber; In a manner that is transmitted to the pharmacy electronically, provided that the prescription is: Transmitted via electronic intermediaries that are certified by the Maryland Health Care Commission; Received by the permit holder’s computer, facsimile machine, or other electronic device; and Maintained by the permit holder in accordance with Regulation .03 of this chapter; or In an oral manner where: Only a pharmacist may take an original oral prescription by a voice messaging system or by phone with the pharmacist reading back the prescription to the prescriber or the prescriber’s agent; and The pharmacist promptly reduces the oral prescription to writing. The requirement of §A(2)(b)(i) of this regulation does not apply to prescriptions transmitted electronically within: A closed system of a group model health maintenance organization as defined in Health-General Article, §19-713.6, Annotated Code of Maryland; or Any other closed system that does not utilize an intermediary for transmission of prescriptions.