url: {url}
elements:
    {element-name-1}: [${predefined-element-name}|{selector} >> ] {selector}
    ...
    {element-name-N}: [${predefined-element-name}|{selector} >> ] {selector}

----------------------------------------------------------------

url:
    <url>

element-name-*:
    <string>

predefined-element-name:
    <string>, name of an element that has previously been defined

selector:
    <selector>