Notation:
<!ATTLIST element-name attribute-name type default-value>
Use the same ATTLIST definition to declare multiple attributes.
<!ATTLIST element-name attribute-name1 type1 default-value1 attribute-name2 type2 default-value2>
Equivalent of:
<!ATTLIST element-name attribute-name1 type1 default-value1 <!ATTLIST element-name attribute-name2 type2 default-value2>