the most important think is which rendering engine you're using: IE or Webkit.
Because you're working on MC9090-G the supported option is IE and I suggest you to stick to this option. Webkit is a much modern rendering engine but requires resources (memory and CPU) not available on the MC9090.
Said that, you can use this compatibility matrix to see which API are available on the IE based Enterprise Browser.
Thanks for your help. I'm using IE, but that link you posted is exactly what I needed - for this question and many others. I guess I'll be sticking with META tags for the barcode portion for now since I'm on IE.