Query: How do police identify someone as belonging to an ethnic group?
Context: One is the system used in the 2001 Census when individuals identify themselves as belonging to a particular ethnic group: W1 (White-British), W2 (White-Irish), W9 (Any other white background); M1 (White and black Caribbean), M2 (White and black African), M3 (White and Asian), M9 (Any other mixed background); A1 (Asian-Indian), A2 (Asian-Pakistani), A3 (Asian-Bangladeshi), A9 (Any other Asian background); B1 (Black Caribbean), B2 (Black African), B3 (Any other black background); O1 (Chinese), O9 (Any other). The other is categories used by the police when they visually identify someone as belonging to an ethnic group, e.g. at the time of a stop and search or an arrest: White – North European (IC1), White – South European (IC2), Black (IC3), Asian (IC4), Chinese, Japanese, or South East Asian (IC5), Middle Eastern (IC6), and Unknown (IC0). "IC" stands for "Identification Code;" these items are also referred to as Phoenix classifications.