Inside XML

Attributes

We've already discussed attributes in some detail; they're those name/value pairs that you can use in start tags and empty tags to provide additional information for an element. Here's an example; in this case, I'm adding an attribute named TYPE to the <CUSTOMER> tag to indicate what type of customer a person is:

<CUSTOMER TYPE = "excellent">
        <NAME>
            <LAST_NAME>Smith</LAST_NAME>
            <FIRST_NAME>Sam</FIRST_NAME>
        </NAME>
        <DATE>October 15, 2001</DATE>
    .
    .
    .

You can use attributes like this one and assign them values in XML documents, but unless you also declare them, your document won't be valid. You can declare a list of attributes for an element with the <!ATTLIST> element in the DTD. Here's the general form of an <!ATTLIST> element: ...