+<!ELEMENT NUMBER EMPTY>
+<!ATTLIST NUMBER
+ value NMTOKEN #REQUIRED>
+
+<!-- STAR expands only to objects of the specified dir before the last "/":
+ ex. cic:/Algebra/* expands to every object in Algebra only -->
+<!-- TWOSTARS expands till the most complete name (with extension if not
+ specifified) -->
+<!-- QUESTIONMARK matches one character except "/" -->