These are the logical operators that can be used when specifying a selection predicate.

typedef enum cssm_db_operator {
    CSSM_DB_EQUAL = 0,
    CSSM_DB_NOT_EQUAL = 1,
    CSSM_DB_APPROX_EQUAL = 2,
    CSSM_DB_LESS_THAN = 3,
    CSSM_DB_GREATER_THAN = 4,
    CSSM_DB_EQUALS_INITIAL_SUBSTRING = 5,
    CSSM_DB_EQUALS_ANY_SUBSTRING = 6,
    CSSM_DB_EQUALS_FINAL_SUBSTRING = 7,
    CSSM_DB_EXISTS = 8
} CSSM_DB_OPERATOR, *CSSM_DB_OPERATOR_PTR;