The simplest usage of a DTD involves actually adding the DTD into
the prolog portion of your XML document, just after the XML processing instruction.
The skeleton (not quite valid) of a DTD looks something like the following:
<?xml version = "1.0" encoding="UTF-8" standalone = "yes"?>
<!DOCTYPE ROOT_ELEMENT_NAME [
ELEMENT_DEFINITIONS_GO_HERE
]>
BODY_GOES_HERE.......
In this case we declare a document with a root element called
ROOT_ELEMENT_NAME. For example, we might use the following syntax for
our CONTACTS document
<?xml version = "1.0" encoding="UTF-8" standalone = "yes"?>
<!DOCTYPE CONTACTS [
ELEMENT_DEFINITIONS_GO_HERE
]>
BODY_GOES_HERE.......