The PC File System provides the following information for each file:
Table A.1-1PC FILE SYSTEM FILE INFORMATION
|Filename||1 to 8 characters|
|Extension||0 to 3 characters|
|Time||Time of last modification (or creation)|
|Date||Date of last modification (or creation)|
|Size||Size of file (in bytes)|
The PC File System Filename shall correspond to a DICOM File ID Component. The PC File System Extension for a DICOM file shall not contain any characters. The PC File System date and time shall be used to provide the DICOM facilities for examining the modification or creation date and time. Unused characters in Filename and Extension (see Table A.1-1) should be filled with null characters.
Notes: 1. The PC File System does not specify or control the time base used for date and time. Coordination of reference time zones is outside the scope of this standard.
2. The typical written form of a filename is filename.extension (e.g. "FILE.EXT"). The period between filename and extension is a convention used in most programs for entering and displaying the filename and extension. The period is not actually recorded on disk and is not permitted as part of a filename. A file with no extension is recorded as a file with zero extension characters (i.e. all null filled) although it is often written and displayed without the period.
The PC File system does not provide ownership or access control facilities. Write protection is addressed in the relevant physical media specific annex. Protection mechanisms are not available for the generic PC File System.