In the javadoc for DatabaseMetaData.getFunctionParameters() it says

# PARAMETER_TYPE Short => kind of parameter:

    * functionParameterUnknown - nobody knows
    * functionParameterIn - IN parameter
    * functionParameterInOut - INOUT parameter
    * functionParameterOut - OUT parameter
    * functionReturn - function return value

But DatabaseMetaData does not define the constant
'functionReturn'. But it DOES define 'functionParameterReturn'