-<!ELEMENT thresholds (threshold)+>
-<!ELEMENT threshold (description , levels)>
-<!ELEMENT description (CDATA)>
-<!ELEMENT levels (CDATA)>
-<!ATTLIST threshold map ID #REQUIRED>
-<!ATTLIST levels width CDATA #REQUIRED>
-<!ATTLIST levels height CDATA #REQUIRED>
-<!ATTLIST levels divisor CDATA #REQUIRED>
+ <!ELEMENT thresholds (threshold)+>
+ <!ATTLIST thresholds xmlns CDATA #FIXED ''>
+ <!ELEMENT threshold (description,levels)>
+ <!ATTLIST threshold xmlns CDATA #FIXED '' alias NMTOKEN #IMPLIED
+ map NMTOKEN #REQUIRED>
+ <!ELEMENT description (#PCDATA)>
+ <!ATTLIST description xmlns CDATA #FIXED ''>
+ <!ELEMENT levels (#PCDATA)>
+ <!ATTLIST levels xmlns CDATA #FIXED '' divisor CDATA #REQUIRED
+ height CDATA #REQUIRED width CDATA #REQUIRED>