title: What can I control with YAML header options in pandoc?
body: <p>Only by chance did I see an example document using the <code>toc: true</code> line in their YAML header options in a Markdown file to be processed by Pandoc. And the <a href="http://johnmacfarlane.net/pandoc/README.html">Pandoc docs</a> didn't mention this option to control table of contents using the YAML header. Furthermore, I see somewhat arbitrary lines in example documents on the same Pandoc readme site.</p>
  
  <p>Main question:</p>
  
  <ul>
  <li>What Pandoc options are available using the YAML header? </li>
  </ul>
  
  <p>Meta-question:</p>
  
  <ul>
  <li>What determines the available Pandoc options that are available to set using the YAML header?</li>
  </ul>
  
  <p>Note: my workflow is to use Markdown files (<code>.md</code>) and process them through Pandoc to get PDF files. It has hierarchically organized manuscript writing with math. Such as:</p>
  
  <pre><code>pandoc --standalone --smart \
      --from=markdown+yaml_metadata_block \
      --filter pandoc-citeproc \
      my_markdown_file.md \
      -o my_pdf_file.pdf
  </code></pre>