Specify conditions using a Ditaval file
By default, if at least one Ditaval file exists in the Content Store, the Ditaval option appears in the Generate Output dialog.
To implement Ditaval files in your deployment, make sure that your DITA Open Toolkit transformation handles Ditaval files to generate output. Otherwise, filtering will not be applied.
You must also set the Ditaval file name in the
               build.xml file by calling the
               ot_build_add_ditaval_ifpresent target in the transformation scenario
            target. The ot_build_add_ditaval_ifpresent sets the
               args.filter parameter in the build.xml
            file.
To specify conditions using Ditaval:
