title: How can I specify pandoc's markdown extensions using a YAML block?
body: <h2>Background</h2>
  
  <p>Pandoc's markdown lets you <a href="http://pandoc.org/README.html#general-options" rel="noreferrer">specify extensions</a> for how you would like your markdown to be handled:</p>
  
  <blockquote>
    <p>Markdown syntax extensions can be individually enabled or disabled by appending <code>+EXTENSION</code> or <code>-EXTENSION</code> to the format name. So, for example, <code>markdown_strict+footnotes+definition_lists</code> is strict markdown with footnotes and definition lists enabled, and <code>markdown-pipe_tables+hard_line_breaks</code> is pandoc’s markdown without pipe tables and with hard line breaks.</p>
  </blockquote>
  
  <h2>My specific question</h2>
  
  <p>For a given pandoc conversion where, say, I use <a href="http://pandoc.org/README.html#extension-yaml_metadata_block" rel="noreferrer">grid tables</a> in my source:</p>
  
  <pre><code>pandoc myReport.md --from markdown+pipe_tables --to latex -o myReport.pdf
  </code></pre>
  
  <p><strong>How can I write a <a href="http://pandoc.org/README.html#extension-yaml_metadata_block" rel="noreferrer">pandoc YAML block</a> to accomplish the same thing (specifying that my source contains grid tables?)</strong></p>
  
  <h2>A generalized form of my question</h2>
  
  <p>How can I turn extensions on and off using pandoc YAML?</p>
  
  <h2>Stack Overflow Questions that I don't think completely answer my question</h2>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/30483240/can-i-set-command-line-arguments-using-the-yaml-metadata">Can I set command line arguments using the YAML metadata</a> - This one deals with how to specify output options, but I'm trying to tell pandoc about the structure of my input</li>
  <li><a href="https://stackoverflow.com/questions/26395374/what-can-i-control-with-yaml-header-options-in-pandoc">What can I control with YAML header options in pandoc?</a> - Answerers mention pandoc's templates, but neither the <a href="https://github.com/jgm/pandoc-templates/blob/8ea41996bf982835ab0d7559d2801e93c8b8f91b/default.latex" rel="noreferrer">latex output</a> template nor the <a href="https://github.com/jgm/pandoc-templates/blob/c08ed3f61a5dda0a33cda08106140be5a5cd6da4/default.markdown" rel="noreferrer">markdown template</a> indicate any sort of option for <code>grid_tables</code>. So, it's not clear to me from these answers how knowing about the templates will help me figure out how to structure my YAML.</li>
  </ul>
  
  <h2>There may also not be a way to do this</h2>
  
  <p>It's always possible that pandoc isn't designed to let you specify those extensions in the YAML. Although, I'm hoping it is.</p>