The map-config.dtd is located in the BASEDIR/smarts/conf/maps directory:

<?xml encoding="ISO-8859-1"?>
<!ELEMENT  map_gifconfig  (map | repos | image)*>
<!ELEMENT map (#PCDATA)>
<!ATTLIST map
 class  CDATA   #REQUIRED
 class  (String | Boolean | Time | Integer | Float | Percentage )  "String"
>
<!ELEMENT repos (#PCDATA)>
<!ATTLIST repos
 class  CDATA   #REQUIRED
 class  (String | Boolean | Time | Integer | Float | Percentage )  "String"
>
<!ELEMENT image (#PCDATA)>