Which of the following is NOT a resource for site coordinator training?

The correct choice being identified as the resource that is NOT used for site coordinator training aligns with the nature of the listed materials. Form 1040 is primarily a tax return form that individuals use to report their annual income to the IRS. It serves as an essential document for taxpayers rather than a training resource.

On the other hand, the other choices are publications designed specifically to assist in training and providing guidance for site coordinators. For example, Pub 5683 and Pub 5166 are publications that contain relevant information and guidelines to aid in the operation of VITA/TCE programs, including training materials, procedures, and best practices for effective service delivery. Pub 5838 is similarly focused on training resources and support for volunteers in the program. Thus, Form 1040, while critical to tax preparation, does not serve as a training resource for coordinators in the context of VITA/TCE programs.