The specification states the following -:
These fields contain the user code. Minimum code length is 4 and maximum 10 ASCII digits.
However it seems that some devices (eg RFID readers) are not using ASCII, but are sending binary data. Is this acceptable - it seems to go against the standard?
63 03 00 00 8F D8 C3 0D 01 20 02 80 00 00