CTI (Customer Type Indicator) Codes
These consist of four identifiers that describe transactions by the type of customer for which a trade is effected. The four codes are: (1) trading by a person who holds trading privileges for his or her own account or an account for which the person has discretion; (2) trading for a clearing member’s proprietary account; (3) trading for another person who holds trading privileges who is currently present on the trading floor or for an account controlled by such other person; and (4) trading for any other type of customer. Transaction data classified by the above codes are included in the trade register report produced by a clearing organization.
Source: Commodity Futures Trading Commission