title: Which HTTP method to use: PUT or DELETE?
body: <p>I want to design my rest endpoint with the appropriate method for the following scenario.</p>
  
  <p>There is a group. Each group has members. A member has to be approved by the group admin in order to become a member. If the admin rejects, the user cannot become a member of the group.</p>
  
  <p>I have the following endpoints to address this scenario.</p>
  
  <ol>
  <li><p>When a user joins a group
  <code>POST   /projects/api/v1/projects/{project id}/members/{member id}</code></p></li>
  <li><p>For approving membership
  <code>PUT   /groups/api/v1/groups/{group id}/members/{member id}/approve</code> to approve membership</p></li>
  </ol>
  
  <p>However, I am having trouble deciding the right endpoint for rejecting membership.
  Should I use</p>
  
  <pre><code>PUT   /projects/api/v1/projects/{project id}/members/{member id}/reject
  </code></pre>
  
  <p>or</p>
  
  <pre><code>DELETE  /projects/api/v1/projects/{project id}/members/{member id}
  </code></pre>