I'm having a tough time understanding the process for adding to the catalog. I am trying to make oxygen default to the 1.7.5.2 Docbook version (which was released a few weeks ago). I want to keep a local version available on my Windows machine. I understand that I need to add something to the catalog, but where? First, I see C:\Program Files (x86)\Oxygen XML Editor 10\frameworks\docbook\xsl\catalog.xml has this: <?xml version="1.0" encoding="utf-8"?> <catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> <!-- XML Catalog file for DocBook XSL-NS v1.75.1 --> <rewriteURI uriStartString="http://docbook.sourceforge.net/release/xsl-ns/current/" rewritePrefix="./"/> <rewriteSystem systemIdStartString="http://docbook.sourceforge.net/release/xsl-ns/current/" rewritePrefix="./"/> <rewriteURI uriStartString="http://docbook.sourceforge.net/release/xsl-ns/1.75.1/" rewritePrefix="./"/> <rewriteSystem systemIdStartString="http://docbook.sourceforge.net/release/xsl-ns/1.75.1/" rewritePrefix="./"/> </catalog> I'm not 100% sure, how I'd edit this file. Oxygen tells me that this file isn't editable (because it's under Program Files, not user space). Would the appropriate syntax be something like this: <rewriteURI uriStartString="http://docbook.sourceforge.net/release/xsl-ns/1.75.2/" rewritePrefix="I:\My Documents\xml\docbook-xsl-1.75.2\"/> <rewriteSystem systemIdStartString="http://docbook.sourceforge.net/release/xsl-ns/1.75.2/" rewritePrefix="I:\My Documents\xml\docbook-xsl-1.75.2\"/> If I created an identical catalog.xml in my user folder (I:\My Documents\xml\docbook-xsl-1.75.2\) but switched out 1.7.5.2 for 1.7.5.1, would that be right? Then Options --> Preferences --> XML Catalog --> Add new catalog --> browse for this new catalog.xml is there an easy way for me to verify that the new local version of xsl file is actually being used? If I just declare I<xsl:import href="http://docbook.sourceforge.net/release/xsl/current/epub/docbook.xsl"/> in my stylesheet, would that be enough (while taking slight hits on performance while the file is being downloaded). Thanks. Robert Nagle