Modularization methodology

Modularization is based on DTD fragments

• In file xhtml-image-1.mod:

  <!ELEMENT img  "EMPTY">

  <!ATTLIST img

         %Common.attrib;

         src       %URI.datatype;      #REQUIRED

         alt       %Text.datatype;     #REQUIRED

         longdesc  %URI.datatype;      #IMPLIED

         height    %Length.datatype;   #IMPLIED

         width     %Length.datatype;   #IMPLIED>

• In XHTML-XX DTD:

  <!ENTITY % xhtml-image.mod

     PUBLIC "-//W3C//ELEMENTS XHTML Images 1.0//EN"

     "xhtml-image-1.mod" >

  %xhtml-image.mod;