This parameter specifies the XML document that describes text translations (and other locale-specific information) that is needed by the stylesheet to process the DocBook document.

This parameter is internal to the stylesheet. To point to an external XML document with a URI or a file name, you should use the custom-localization-file parameter instead.

However, inside a custom stylesheet (not on the command-line) this paramter can be set to the XPath expression document(''), which will cause the custom translations directly embedded inside the custom stylesheet to be read.