38 C.F.R. § 21.314
Pursuit of training under special conditions
A veteran is required to pursue a rehabilitation program at a rate which meets the requirement for full- or part-time participation described in §§ 21.310 and 21.312. However, a veteran may pursue a rehabilitation program at a lesser rate, if such pursuit is a part of the veteran's plan. Subsistence allowance is not payable during such periods.