using more than one DTD file
If we need more than one DTD file for one XUL file, we're using external entities
inside the XUL file's DOCTYPE declaration.
Sample XUL: openLocation.xul
<?xml version="1.0"?>
<!DOCTYPE dialog [
<!ENTITY % brandDTD SYSTEM "chrome://global/locale/brand.dtd" >
%brandDTD;
<!ENTITY % openDialogDTD SYSTEM "chrome://communicator/locale/openLocation.dtd" >
%openDialogDTD;
]>
<dialog ... title="&brandShortName; - &caption.label;">
...
<description>&enter.label;</description>
...
<menuitem value="0" id="currentWindow" label="&topWindow.label;"/>
...
</dialog>
Sample DTD: openLocation.dtd
<!ENTITY caption.label "Open Web Location">
<!ENTITY enter.label "Enter the web location (URL), or specify the local file you would like to open:">
<!ENTITY topWindow.label "Current Navigator window">
Sample DTD: brand.dtd
<!ENTITY brandShortName "Mozilla">