All transmissions will be disseminated in USASCII, unmodified. Each character may consist of seven (7) data bits, plus an eighth (8th) bit for parity (vertical redundancy check). CME Group uses the synchronous protocol utilizing only the following control characters SOH, STX and ETX characters. The synchronous protocol allows for the use of lower case characters however, lower case characters will not be utilized for Contract ID codes, Option ID codes or BAT codes.
Uppercase and Lowercase Characters Defined, Justified and Filled
Uppercase and Lowercase will be defined as the capital letters A through Z as well as ASCII space. Commodity Codes, Instrument Codes, and Combination ID and Cash Instrument Descriptions may not begin with a space, but may end with multiple spaces.
Numeric Characters Defined, Justified and Filled
Numeric Characters, Defined, Justified and Filled Numeric characters are defined as the numerals, 0 through 9, as well as ASCII space. Fields containing numeric characters will be right justified and ASCII zero (0) filled as appropriate. If there is no data available to fill a numeric field (as contrasted with the case where the appropriate value for the field is zero), then the field will be filled with ASCII space characters. Numeric fields subject to ASCII space character fill will be identified where appropriate.
Maximum ITC Message Length
The number of bytes in any single message, including control characters, will typically not exceed 300 bytes.