So, I downloaded Evernote, made a couple of notes, exported the Notebook containg those 3 notes & find its an XML file
Looks like this is at the start of each note...
"http://xml.evernote.com/pub/enml2.dtd"><en-note><div>
Note1 & Note2 are the contents of the 3 notes...
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE en-export SYSTEM "http://xml.evernote.com/pub/evernote-export3.dtd">
<en-export export-date="20210425T201646Z" application="Evernote" version="10.10.5">
<note>
<title>Untitled Note</title>
<created>20210325T201545Z</created>
<updated>20210325T201600Z</updated>
<note-attributes>
</note-attributes>
<content>
<![CDATA[<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE en-note SYSTEM "http://xml.evernote.com/pub/enml2.dtd"><en-note><div>Note1</div><div><br /></div></en-note> ]]>
</content>
</note>
<note>
<title>Untitled Note</title>
<created>20210325T201602Z</created>
<updated>20210325T201608Z</updated>
<note-attributes>
</note-attributes>
<content>
<![CDATA[<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE en-note SYSTEM "http://xml.evernote.com/pub/enml2.dtd"><en-note><div>Note2</div></en-note> ]]>
</content>
</note>
</en-export>