<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE bookstore [
    <!ELEMENT bookstore (book+)>
    <!ELEMENT book (title,author,publisher,price)>
    <!ATTLIST book category CDATA #REQUIRED>
    <!ELEMENT title (#PCDATA)>
    <!ELEMENT author (#PCDATA)>
    <!ELEMENT publisher (#PCDATA)>
<!ELEMENT price (#PCDATA)>
]>
<bookstore>
    <book category="fiction">
        <title>GGG</title>
        <author>hhh</author>
        <publisher>hi</publisher>
        <price>2000</price>
    </book>
</bookstore>