title: Is PUT/DELETE idempotent with REST automatic?
body: <p>I am learning about REST and PUT/DELETE, I have read that both of those (along with GET) is idempotent meaning that multiple requests put the server into the same state.</p>
  
  <p>Does a duplicate PUT/DELETE request ever leave the web browser (when using <code>XMLHttpRequest</code>)? In other words, will the server be updating the same database record for each PUT request, or will duplicate requests be ignored automatically?</p>
  
  <p>If yes, how is using PUT or DELETE different from just using POST?</p>
  
  <p>I read an article which suggested that RESTful web services were the way forward. Is there any particular reason why HTML5 forms do not support PUT/DELETE methods?</p>