Table schema:
CREATE TABLE policies (customer_id VARCHAR, policy_type_code VARCHAR); CREATE TABLE customers (customer_details VARCHAR, customer_id VARCHAR)

Question: Find the names of the customers who have an deputy policy.
SQL: SELECT DISTINCT t2.customer_details FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id = t2.customer_id WHERE t1.policy_type_code = "Deputy"