<!ELEMENT PMT_SOURCE_RECROD (clientNumber, paymentSource, description?, cardName?, cardExpiry, billingZip?, cardSecurityCode?, dsoChecksum)> <!ELEMENT clientNumber (#PCDATA)> <!ELEMENT paymentSource (#PCDATA)> <!ELEMENT description (#PCDATA)> <!ELEMENT cardName (#PCDATA)> <!ELEMENT cardExpiry (#PCDATA)> <!ELEMENT billingZip (#PCDATA)> <!ELEMENT cardSecurityCode (#PCDATA)> <!ELEMENT dsoChecksum (#PCDATA)>