title: Google Docs API: Do document resource ID's ever change?
body: <p>Is it wise to build a website like environment where all links are based on resource ID's from documents?
  Did document ID's ever change in the past, can/will they in the future?</p>
  
  <p>Past week we were surprised to see a collection where it looks like some ID's of documents had changed, is this possible?</p>