The DOCTYPE Declarations

If you want to declare entities, you MUST do so within the document DOCTYPE declaration that always follows the prolog, (DTD and XML Declaration), and looks like the following:

<?xml version="1.0"?>
<!DOCTYPE myDocument [     
...here is where you declare 
your entities....
]>
<myDocument>
...here is the body of your document....
</myDocument>

Thus, you might have something like the following, (Consider how much easier changing office addresses is when you use entities!):

    <?xml version="1.0"?>
    <!DOCTYPE CLIENTS [     
          <!ENTITY NinthFloorAddress 
		"2345 Broadway St. Floor 9">
          <!ENTITY EighthFloorAddress 
		"2345 Broadway St. Floor 8">
          <!ENTITY SeventhFloorAddress 
		"2345 Broadway St. Floor 7">
          ]>
    <CLIENTS>
    <CLIENT>
    <NAME>Barnaby Hazen</NAME>
    <ADDRESS>&NinthFloorAddress;</ADDRESS>
    <PHONE>x345</PHONE>
    </CLIENT>

    <CLIENT>
    <NAME>David Florey</NAME>
    <ADDRESS>&NinthFloorAddress;</ADDRESS>
    <PHONE>x111</PHONE>
    </CLIENT>

    <CLIENT>
    <NAME>Danette Ellsworth</NAME>
    <ADDRESS>&NinthFloorAddress;</ADDRESS>
    <PHONE>x346</PHONE>
    </CLIENT>

    <CLIENT>
    <NAME>Rachna Dhamija</NAME>
    <ADDRESS>&SeventhFloorAddress;</ADDRESS>
    <PHONE>x289</PHONE>
    </CLIENT>

    <CLIENT>
    <NAME>Kristin Mancuso</NAME>
    <ADDRESS>&EighthFloorAddress;</ADDRESS>
    <PHONE>x945</PHONE>
    </CLIENT>
    </CLIENTS>

Parameter Entities
Introduction to XML For Web Developers | Table of Contents
Entity References