title: IBM Speech to Text Alphanumeric String recognition?
body: <p>In trying to get Speech to Text (IBM Voice Gateway IVR app) to recognize alpha-numeric character strings, I am wondering if I could create a custom grammar or entity that would restrict STT to recognizing just individual letters and numbers, excluding words altogether. For example, here's a typical string: 20Y0H8C. Watson comes back with words and numbers, like "two" instead of "2". Digit strings work fine. I realize that letter recognition is problematic with typical ASR, but I'm hoping Watson is up to the task. I noticed there are no system entities for alphanumeric characters.  Any suggestions are much appreciated.</p>