The Always Use Document DDF DesignMerge preference determines whether DesignMerge always uses a special type of DDF named the Document DDF or allows you to use DDFs that you name.

This preference is a check box option that is available on the DesignMerge Preferences dialog (DesignMerge > Preferences).

• Select this preference to always use the Document DDF (this is the default setting for DesignMerge Pro).
• Deselect this preference to also use Named DDFs (this is the default setting for DesignMerge Catalog).

For more information, see the Document DDF versus Named DDF, which one to use? knowledgebase article.