Final answer:
The standard form used to turn in supply items is DD Form 1348-1a, and the using activity is required to prepare 3 copies of the form.
Step-by-step explanation:
When turning in supply items, the form normally used is the DD Form 1348-1a, and the using activity must prepare 3 copies. This form is utilized by the Department of Defense for requisitioning, issue, and turn-in transactions including those from a using activity. It is important to complete all the necessary parts of the form accurately and make the required number of copies to ensure proper processing and documentation.