Final answer:
Form C is the form used to initially classify all persons newly admitted into DC custody according to Directive 4100R-D, as part of the standard intake process to determine custody level.
Step-by-step explanation:
The form used to initially classify all persons newly admitted into DC custody as per Directive 4100R-D is Form C. This form is an integral part of the intake process and ensures that each individual is assessed and classified based on specific criteria to manage their custody level appropriately. The Directive 4100R-D outlines the processes and protocols that must be followed when admitting new individuals into the DC Department of Corrections system, ensuring consistency and accuracy in classification.