Validation and Namespaces

DTDs, unfortunately, are not namespace aware. When writing a DTD for a document that uses namespaces, you must declare the prefixed names, as shown below.

<!ELEMENT chess:game (chess:move+)>
<!ELEMENT chess:move (#PCDATA)>

If the documents don't use a prefix, you declare the unprefixed names instead.

<!ELEMENT game (move+)>
<!ELEMENT move (#PCDATA)>

You must further declare the namespace attributes just as you would any other attribute.

<!ATTLIST chess:game xmlns:chess
    CDATA "http://namespaces.cafeconleche.org/chess" #FIXED>
<!ATTLIST game xmlns CDATA
    "http://namespaces.cafeconleche.org/chess" #FIXED>

This is rather annoying and inconvenient. Fortunately, the parameterization techniques discussed in Item 7 enable ...

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