HPXML has two element types: 1.) data elements, and 2.) parent elements that have children.
This element is a parent element it's children are listed in the tree view in this box.
If the children are a sequence, then the child elements are required to be in the order specified.
Bolded elements are required. Non-bold elements are optional.
If the children are a choice, then one and only one of the child elements are allowed.
Pressing the triangle next to an element will open it up and show the children of that element.
Clicking on an element name navigates to the page for that element for more details.
