 </li>
      <li>
        <a href="#Requirements">3. Requirements</a>
      </li>
      <li>
        <a href="#Terms">4. 
        Terminology</a>
      </li>
      <li>
        <a href="#TypeSystem">5. 
        Type System</a>
      </li>
      <li>
        <a href="#ProcedureCall">6. 
        Procedure Call (Request)</a>
        <ul class="toc">
          <li>
            <a href="#RequestHeaders">6.1. HTTP Header Requirements</a>
          </li>
          <li>
            <a href="#PostProcedureCall">6.2.