title: AMAZON.FIVE_DIGIT_NUMBER does not exist to capture zipcode in Amazon Alexa
body: <p>Alexa certification feedback says to use slot type "AMAZON.FIVE_DIGIT_NUMBER" for zipcodes. That would make sense, but it doesn't actually exist!</p>
  
  <p>When I include this slot type, I am unable to save the intent json It gives the error: <em>"Unknown slot type 'AMAZON.FIVE_DIGIT_NUMBER' for slot 'POSTCODE'"</em>.</p>
  
  <p>I can replace with AMAZON.FOUR_DIGIT_NUMBER and it works great and captures all 5 digits nicely. However, this issue was mentioned as a reason for failed certification.</p>
  
  <p>I can replace with AMAZON.NUMBER which kinda works (as per suggestion in certification), but often only captures the first 4 digits, ironically not as well as AMAZON.FOUR_DIGIT_NUMBER which almost always captures all 5.</p>
  
  <p>I want to pass certification but the AMAZON.NUMBER seems to give inferior results.</p>
  
  <p>What should I do?</p>