Modify the main map file to reference the subordinate file.
- Make sure the first line of the main map file is:
 
- Between the XML version declaration and the opening adapter tag, add these
               lines:
 <!DOCTYPE adapter SYSTEM "adapter.dtd" [
]>
  
- For each subordinate map file:
- Between the two lines just added, add:
 <!ENTITY SUBREF SYSTEM "SUBFILE">
  where SUBREF is a string to reference the subordinate file and SUBFILE is the
                     path and filename of the subordinate file itself. Enclose the path and filename
                     in quotation marks.
 
- Remove the content that you put in the subordinate map file.
 
- Insert a string like the following to include the content from the subordinate
                     map file:
 where SUBREF is the string you specified to reference the subordinate
                     file.