This contains the raw binary data uploaded by the client
browser. It may be encoded in a format such as MacBinary which is
why it is not generally useful. For most uploads the RawData
property will be identical to the Data property. The representation
of the data is a Variant containing a SafeArray of Bytes.
The lower bound of this array is always zero and the upper bound
is equal to the size of the data minus one. If no data has been
uploaded the upper bound will be minus one.