The FSU shall be able to recognize a File-set and the corresponding DICOMDIR containing the Media Storage Directory SOP Class. A valid File-set may contain only a DICOMDIR and no other files. If a File-set contains other files with stored SOP Instances, the FSU shall be capable of invoking M-READ Operations to access the content of the Files of the File-set. The manner in which this is achieved is beyond the scope of the DICOM Standard.

The FSU shall support the Media Storage Operation M-INQUIRE FILE and the M-INQUIRE FILE-SET.

The FSU shall be able to create one or more new Files belonging to the File-set by invoking M-WRITE Operations with SOP Instances that meet the requirements of the corresponding IOD. It is the responsibility of the FSU to ensure that the M-WRITE results in the creation of a correctly formatted DICOM File. The manner in which this is achieved is beyond the scope of the DICOM Standard. The FSU shall be able to update the contents of the DICOMDIR File by using M-DELETE and or M-WRITE Operations.