Yes. Atom feed files are XML (eXtensible Markup Language) documents. Atom feed files must be well-formed XML documents, respecting the following XML rules.► The first line must be the "xml" processing instruction with "version" and "encoding" attributes.► There must be only one root element in a single XML document.► All elements must be closed with the closing tags.► One element can be nested inside another element.► One element can not be partially nested inside another element.► Element attribute values must be quoted with double quotes.► Special characters in element attribute values or element contents must be protected using entities, like < and >.