Can contain a combination of text and child elements.
Plain text such as CSV file content.
A single URI.
Data in JSON format.
e.querySelector('txt')
e.textContent.split('\n')
setAttribute('src', e.textContent)
JSON.parse(e.textContent)
View this page's source to see the <about> element in use. You can put elements from this namespace into the SVG <metadata> element, and it seems you can do the same with the HTML <template> element.
