Final answer:
Precious metals are categorized under CIIC Code Q, which indicates they are high-value items requiring tighter security controls in inventory management.
Step-by-step explanation:
The CIIC (Controlled Inventory Item Code) used to identify precious metals such as gold, silver, and platinum is Code Q. CIIC is a code that indicates the level of security or control required for inventory management of an item. Precious metals are typically categorized under Code Q because they are considered high-value items that require additional security measures to prevent theft or loss.