This DoD Manual is Volume 2 of a two part manual, DoD Manual 1332.18.
Per this volume:
a. Manual. This manual is composed of several volumes, each containing its own purpose. The purpose of the overall manual, in accordance with the authority in DoD Directive 5136.01 (Reference (a)), is to implement policy, assign responsibilities, and provide procedures for the DES pursuant to DoD Instruction (DoDI) 1332.18 (Reference (b)).
b. Volume. This volume implements policy, assigns responsibilities, and provides procedures for using the IDES process to refer, evaluate, and return to duty, separate, or retire Service members for disability pursuant to Title 10, United States Code (Reference (c))."
Note that per DoDI 1332.18, DTM 11-015 (the previous IDES regulation) is cancelled.