title: How to correctly utilize Zip Code entity for DialogFlow?
body: <p>I'm currently trying to use the built in entity '@sys.zip-code' from DialogFlow (formerly API.AI) for capturing Zip Codes.  However so far it does not seem to recognize any actual zipcodes except those which I explicitly set through training.  It also does not recognize the '5 digit' pattern as a possible match if @sys.phone-numbers is used in another intent (ex: 54545 gets recognized as a phone number, rather than a zip).</p>
  
  <p>Should I upload a list of known zipcodes through the training section to get this working?  Or is there something I'm missing from the built in functionality?  Haven't seen a ton of info online on how to best utilize this entity, so figured I'd ask here before coming up with a custom solution.</p>
  
  <p>Thanks in advance!</p>