Which of the following is NOT a field in the processing custodian layout?

The correct choice for which field is NOT included in the processing custodian layout is Document Type. In the context of managing custodians within a data processing framework, the fields typically focus on identifying and managing the individuals or entities responsible for the data, such as their names and types, as well as any pertinent notes regarding them.

Fields like First Name and Custodian Type are essential for categorizing and identifying custodians effectively. Notes can also be significant for tracking additional information related to each custodian. Document Type, however, pertains more to the categorization of individual documents processed rather than the custodians themselves. Thus, including Document Type in the layout of custodian-related fields is not relevant, making it the correct answer in this context.