The <PersonName> element is a child element of the <Payer> element. The <PersonName> element is the first element under the <Payer> element and is a required element.
The <PersonName> element contains 2 children elements and has a sequence content model. The sequence content model means that there is a particular order to the children elements of the parent element - in this case, the <PersonName> element has a particular order of elements that must be followed.