Filling Out the File Class
The <File> class is identical in all places it appears.
For additional explanation, see the PDS4 Standards Reference, or contact your PDS node consultant.
Following are the attributes you'll find in the <File> class, in label order.
Note that in the PDS4 master schema, all classes have capitalized names; attributes never do.
This is the name of the file, including path information relative to the location of the product label. It is the only required field. It should be in the same case as it actually appears in the archive - although software probably shouldn't assume that case will always be correct.
If you need to cross-reference this file elsewhere in the product label, use this field to assign a short identifier unique to this file. If you don't need to do that, you have no reason to use this attribute.
Remember that this is the creation time for the data file, not the product label. It should be in the standard ISO format: YYYY-MM-DDThh:mm:ss.ss, to whatever the appropriate precision might be. You can specify that the time is UTc by appending Z to the end of the time.
This is the size of the data file in bytes. You will need to specify the unit for this attribute, thus:
The current upper limit on this value is (2^64)-1. If you have a file larger than that ... congratulations?
This is the total number of records in the entire file. The record size would be determined by overall file structure for files with multiple data objects. If you give a number of records for the file, you should usually explain in the <comment> field how a record is defined. For example, in a FITS file you could specify the number of 2880-byte FITS blocks as the number of records in the file, and in the <comment> you should include something like "The record count is the total number of 2880-byte FITS blocks in the file."
Checksum for the data file calculated using the MD5 algorithm.
Room for any additional explanation or caveats you'd care to include about the data file.