3. Naming and Metadata Rules

Owned by Julie Wetherill
Last updated: Sept 23, 2022 by Paul Aloisio


File names on disk

For all files in an object:

  • Maximum number of characters per file name is 100. LTS recommends that file names be kept to 64 characters or less, and that the complete_directory_path + file_name for each file be kept to 255 characters or less.
  • Valid characters in file name prefix are letters, digits, underscores ('_'), and hyphens ('-').
  • File names should not contain spaces.

  • Use a single '.' character to separate the file name prefix from the file extension. In the case of file compression formats used on archive file formats (e.g. TAR), the double extension format is acceptable. For example:


    • file.tar.gz

    • file.tar.Z

    • file.tar.bz2

Files that share a derivative relationship (e.g., a production master .tif file and its related deliverable .jpg or .jp2 file) should share the same file name in order for Batch Builder to determine that the relationship exists (e.g. clocktower.tif and clocktower.jpg).

The file name of a digital file will be changed once the file is in DRS storage. At the point of deposit, DRS assigns each file a numeric DRS identifier. The file name will be the DRS ID followed by the format extension (e.g., 5844020.tif, 5844022.jpg).

The original file name is preserved in DRS metadata. The DRS load report that is sent after a successful DRS deposit will associate the file's DRS ID with the original file name (FILE-ORIGPATH). Also, if you use Batch Builder's default method for assigning owner supplied name, the original file name (minus format extension) will be preserved in DRS metadata as the owner supplied name. In the case of PDS documents, the original filename will be the part of the owner supplied name before the double underscore (e.g. 'doc1' in the owner supplied name 'doc1_ _seq1')

Object and batch directory names on disk

  1. Maximum directory name length is 100 characters.
  2. No spaces are allowed in batch or object directory names.
  3. Valid directory name characters are letters, numbers, underscores ('_') and hyphens ('-').
  • *Note that Batch Builder does not validate these rules and will successfully process the batch with disallowed characters or spaces in batch directory or object directory names. The DRS batch loader is not validating the rules consistently. The DRS batch loader will silently fail (without sending an error report) when a batch with disallowed characters or spaces in batch directory name is dropped off to the DRS dropbox. The DRS loader will successfully load a batch where object directory names contain disallowed characters or spaces. These are known issues and they will be addressed in a later software release.
  • Please make sure to provide only allowed characters in batch directory and object directory names and keep the name length to no more than a 100 characters.
  • This is important because, when in the future the DRS needs to reconstruct the directory or file paths associated with a batch, it may fail if the directory names contain disallowed characters or exceed a 100 character limit. 

File owner supplied names

File owner supplied name (file OSN) serves as an identifier that can be used to link files deposited into the DRS with local information about the files (such as local accession numbers or classification numbers) and with corresponding information in other LTS systems.

An owner supplied name needs to be unique within a DRS Owner Code in following cases:

  • images linked to Shared Shelf using the Shared Shelf AVES loader
  • audio files, if an audio AES-60 playlist will be generated for the files
  • files that are intended to be linked to finding aids using Link-o-matic tool - in this case file OSN needs to be unique and exactly match an EAD component name

Failure to supply a unique OSN in these cases will prevent access to these files.

There are three ways of supplying a file OSN:

  1. Use file name for file OSN. When using this option, set the file name pattern preferences for generating file OSNs in Batch Builder Options menu. See the File name pattern options section of Installation and Setup for more information.
  2. Supply file OSNs using an external mapping file. To find out more about using mapping files see Using External Mapping Files to Supply ownerSuppliedNames, Page Sequence Numbers and Aleph or Alma IDs.
  3. Supply file OSNs on Command Line Interface (CLI) during batch processing. For more details about CLI see Processing Batches Using Command Line Interface.

Recommendations for file owner supplied names:

  • Owner supplied names should not exceed 100 characters.
  • Only alpha-numeric characters and these symbols should be used: periods ('.'), underscores ('_'), and hyphens ('-').

Object owner supplied names

Object owner supplied name (object OSN) serves as an identifier that can be used to link objects deposited into the DRS with local information about them (such as local accession numbers or classification numbers). Each object requires an owner supplied name.

Tip:

Within an Owner Code, the object Owner Supplied Name must be unique.

There are four ways of supplying object OSNs:

  1. Enter Object OSN manually when creating a new object in Batch Builder (Note that you have to create a batch first, before you can create a new object). For the procedure' see a subsection "Manually create [content model] objects from template"' in a section on how to create object batches of a given content model in this Guide (e.g.: Manually create still image objects from template under Creating and processing still image object batches.).
  2. Have BB create object OSNs for you when it is building object batches automatically from template. In this case you need to add object name prefix to file names (the syntax is: 1) for all objects except PDS Document Objects:[object_osn] [filename].[extension]; 2) for PDS Document Objects: [object_osn]--[filename]_ _[pageSeq].[extension]) or supply mapping.txt file in order for BB to associate files with objects. For the procedure' see a subsection "Automatically build [content model] objects from template" in a section on how to create object batches of a given content model in this Guide (e.g.: Automatically build still image objects from template under Creating and processing still image object batches.). See also the File name pattern options section of Installation and Settings for additional information on setting file name patterns in the BB Options dialog.
  3. Supply object OSN using Command Line Interface (CLI) during batch processing (Note that to use this option you need to have an existing object with an object OSN. The new object OSN supplied in CLI overwrites the object OSN that was given to the object at the time it was originally created.). For more details about CLI see Processing Batches Using Command Line Interface.
  4. Supply object OSN using external mapping file during batch processing (Note that to use this option you need to have an existing object with an object OSN. The new object OSN supplied in the external mapping files overwrites the object OSN that was given to the object at the time it was originally created.). To find out more about using mapping files see Using External Mapping Files to Supply ownerSuppliedNames, Page Sequence Numbers and Aleph or Alma IDs.

Recommendations for owner supplied names:

  • The number of characters per owner supplied name should not exceed 100.
  • Only alpha-numeric characters and these symbols should be used: periods ('.'), underscores ('_'), and hyphens ('-').

Required file metadata

The following required metadata needs to be entered for files:

  1. First generation in DRS: "yes" for files that are closest to original such as archival masters; "no" for files that are derived from archival master such as deliverables
  2. Usage class (DEPRECATED): "LOWUSE"  and "HIGHUSE" for files is no longer used. The Storage Class setting is used instead.  Can set as HIGHUSE for consistency.
  3. Role: for images, PDF document files and audio files: "ARCHIVAL_MASTER" should be set for archival quality files; "DELIVERABLE" should be set for delivery files to get Batch Builder to generate a delivery URN and when used with Shared Shelf and Link-o-matic. For files that serve as both archival and delivery files, set both roles "ARCHIVAL_MASTER" and "DELIVERABLE" by using Ctrl Click in Batch Builder.
  4. Quality: set "5" for files that will be linked to Shared Shelf or will be used with Link-o-matic. Set to any other value (with "10" being the highest quality) when files are not used with Shared Shelf or Link-o-matic.
  5. Storage class: Leave this field unselected and Batch Builder will determine storage class based on file characteristics and associated metadata values.

Required object metadata

The following metadata is required for objects:

  1. Owner Code - your DRS Owner Code
  2. Billing Code - your DRS Billing Code
  3. File Access Flags (for all but opaque objects) - set to the access flag that equals to the least restrictive flag of the files in the object
  4. URN Authority path – your URN authority path
  5. URN Resource Name Pattern – set this to one of the valid URN resource name patter values (see Batch Builder hover-over help for values).





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