blowdart

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
   <system.webServer>
      <httpProtocol>
         <customHeaders>
            <add name="X-Clacks-Overhead" value="GNU Terry Prachett" />
         </customHeaders>
      </httpProtocol>
   </system.webServer>
</configuration>

blowdart

<system.webServer>
    <security>
        <requestFiltering>
            <fileExtensions>
                <!-- I KNOW WHAT I AM DOING. I AM JON SKEET -->
                <remove fileExtension=".cs" />
                <add fileExtension=".cs" allowed="true" />
            </fileExtensions>
        </requestFiltering>
    </security>