In certain, probably rare circumstances, you will wish to include parsed
character data as a valid element. Mixing content works as expected.
Thus, the following XML document would be valid.
<?xml version = "1.0" encoding="UTF-8" standalone = "yes"?>
<!DOCTYPE CONTACTS [
<!ELEMENT CONTACTS ANY>
<!ELEMENT CONTACT (NAME | EMAIL | PHONE | #PCDATA)*>
<!ELEMENT NAME (#PCDATA)>
<!ELEMENT EMAIL (#PCDATA)>
<!ELEMENT PHONE (#PCDATA)>
Roger is a swingin' hep cat!