Situations arise in which we may have multiple versions of a particular image or object, for a variety of reasons.
As we cannot foresee all the situations, we will proceed in determining policies in a case by case fashion.
Rule 1. Different format, same original.
Clearly, if another format of the same file is being created, the only change needs to be the extension.
- A jpeg made from the tif file u0003_000608_0000234_0001.tif would be named u0003_000608_0000234_0001.jpg.
- A plain text derivation of the tif file u0003_000608_0000234_0001.tif (created by OCR process or hand-typing into a plain text editor) would be named u0003_000608_0000234_0001.txt.
- Someone reads the letter into a microphone, digitizing the text in audio format. In this case, no pagination is involved, so the filename of the ITEM ends in the extension of the audio format, for example: u0003_000608_0000234.mp3.
- A separate version of the document exists, typed, and we want to OCR it for the content, which then will be applied for indexing and searching the scan of the handwritten (or original document). In this case, the scan of the alternate (typed) version of the document should be put in a separate folder labeled "Transcriptions" and discarded after the OCR text file is created. (This ruling compliments of Jeremiah Colonna-Romano.)
Rule 2. Same format, alternative original.
If, however another tiff is being made of an alternate version of the same object, we need another method.
The reasoning in the last example in Rule 1 is appropriate for a temporary working solution. That is, during the production process, the alternate version will be stored in a separate folder labeled appropriately. In this case, we are storing the scans of the typed transcripts of handwritten documents in a folder labeled "Transcriptions".
If the alternative original is to be kept long term, for example, another publication of a sheet music item we already have, then it should be issued its own item number, as this is (according to PREMIS) another digital object.
Rule 3. Alternative version of same format, same original.
This should be a real issue when we begin to migrate content. The type of object should be recorded in the technical metadata, the item added to the METS record for that object, but the naming should follow the following convention:
One solution is to use foldering to disambiguate.
If folder v002 exists in an item directory, it contains the second version of that item, named identically to the first. Folder v003 would contain the 3rd version, and so forth.
Should descriptive metadata apply to only one version, that should be notated in a comment field in the metadata, and a copy kept in that version's folder. Otherwise, the versioning of descriptive metadata for each item will be kept separate, in the Metadata directory for the item, as described elsewhere (File_Naming_and_Linking_for_LOCKSS).
Rule 4. Different format, alternative original
Follow the ruling that is spelled out in Rule 2.
(updated 2/3/10, Jody DeRidder)