What document outlines identity source requirements for customers lacking a CAC?

The I-9 form is a crucial document that serves to verify the identity and employment eligibility of individuals in the United States. It is particularly relevant for employers who must confirm that employees are legally allowed to work in the country. In instances where an individual does not possess a Common Access Card (CAC), the I-9 form outlines the specific identity source requirements that an employer can accept to verify the person's identity. This form lists acceptable documents that can establish both identity and employment authorization, which is essential for compliance with federal law regarding work eligibility.

The other options do not fulfill this role. The W-2 form is primarily a wage and tax statement, and though it can indicate employment, it does not serve as a tool for identity verification. DD Form 2842 is related to military procedures and does not pertain to identity documentation. Standard Operating Procedures (SOPs) provide guidelines and protocols within an organization but do not specify identity verification sources. Thus, the I-9 form stands out as the correct answer for defining the identity source requirements for customers lacking a CAC.