process.empty.source.toc boolean process.empty.source.toc Generate automated TOC if toc element occurs in a source document? Specifies that if an empty toc element is found in a source document, an automated TOC is generated at this point in the document. Depending on what the value of the generate.toc parameter is, setting this parameter to 1 could result in generation of duplicate automated TOCs. So the process.empty.source.toc is primarily useful as an "override": by placing an empty toc in your document and setting this parameter to 1, you can force a TOC to be generated even if generate.toc says not to.