title: Possible side effect using comma in querystring?
body: <p>I'd like to use <code>,</code> in URL querystring value but <a href="https://stackoverflow.com/a/2375597/361100">it is reserved character</a>. However, we can see many e-commerce sites give comma-galore querystring urls in these days.</p>
  
  <p>What do we consider when we use <code>,</code> in querystring? Should it be encoded as <code>%2c</code> always?</p>
  
  <p>Note that my server-side frameworks are ASP.NET WebApi, dJango, and Node.js.</p>