The Directory Record is based on the specification of Section F.3. It is identified by a Directory Record Type (0004,1430) of Value "PLAN". Table F.5-40 lists the set of Keys with their associated Types for such a Directory Record Type. The description of these Keys may be found in the Modules related to the Plan IE of the RT-specific Plan IODs. This Directory Record shall be used to reference one of the class of Plan SOP Instances having a Modality (0008,0060) of "PLAN", such as the RT Beams Delivery Instruction IOD or the RT Brachy Application Setup Delivery Instruction IOD. This type of Directory Record may reference a Lower-Level Directory Entity that includes one or more Directory Records as defined in Table F.4-1.