chromium/third_party/blink/web_tests/http/tests/xsl/resources/xsl-using-document-with-external-entity-target-document.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE p [
<!ENTITY secretfile SYSTEM "file:///secret/file">
<!ENTITY secreturl SYSTEM "http://example.com">
]>
<p>
    &secretfile;
    &secreturl;
</p>