Install the ISO entity sets

Extract the files

Extract the contents of the ISO entity archive into a new directory in your SGML tree, e.g. C:\User\default\SGML\ISOents. These standardized entities are referenced by DocBook, but as they can be shared by other DTDs, it is better to keep them apart from DocBook proper.

Modify docbook.cat

The file docbook.cat that you installed with the DocBook DTD contains the references to the ISO entities. However, you will have to adjust the paths and the filenames. E.g. modify the following line:

     
      PUBLIC "ISO 8879:1986//ENTITIES Diacritical Marks//EN" "iso-dia.gml"
      
   

to read:

     
      PUBLIC "ISO 8879:1986//ENTITIES Diacritical Marks//EN" "../../ISOents/isodia"
      
   

Look up all ISO entity files which appear in docbook.cat and modify the entries accordingly.