The World Digital Library uses UNIX servers for production work as well as display to the public. Because UNIX servers sometimes handle files differently than Windows or other types of machines, please follow these guidelines when preparing files for the WDL.
General Rules for Directory and File Names
- Each image or set of images should be associated with a metadata record. When images and metadata records are submitted to WDL, it should be clear which metadata record is associated with which images. This is usually achieved through the use of a digital identifier that appears in each metadata record. This digital identifier should be in the name of the directory or file name containing the images.
- Use only ASCII characters (with the exception of the characters listed below) and Western/Arabic numbers (0-9). If your system requires use of other character sets, please send the WDL office a sample set of files for testing purposes. For more information on ASCII see the Wikipedia article on ASCII characters.
- Lower case file names are preferred. Note that directory and file names are case sensitive. This means that my_file is not the same as MY_file or my_File.
- Use three-letter extensions for file names (.tif for TIFF images, .jpg for JPEGs, etc.)
- Although many systems can handle long directory and file names, lengthy names (beyond 16 characters) are not optimal. Try to keep directory and file names to less than 16 characters.
The following characters should NOT be used in directory or file names:
Blank spaces should not be used in directory or file names. Blank spaces can be replaced with underscores. For example, "filename 1" could be "filename_1."
Multi-image items include multiple images in which the sequence of presentation is important. Examples include:
- Single books
- Multi-volume books
- Sheet music
- Photo Albums
Sequential Filenaming for Multi-Image Items
Since the order of display is important, files should be named sequentially in the order in which the physical volume would be viewed. This is an example of proper sequential ordering:
- Directory/Digital ID name: 200149093
Leading zeroes are extra zeroes at the beginning of a file name to give each file in an item the same number of digits in numeric ordering. If ordering is relevant, leading zeroes must be used to ensure proper display. Consistency in the number of digits used in a naming scheme is very important.
This is an example of incorrect ordering. Three files named 1.tif, 11.tif and 2.tif will appear in this order:
This is an example of correct ordering. Three files named 01.tif, 11.tif and 02.tif will appear in this order:
Please make sure files have an appropriate number of leading zeroes.
Note that numbers come before alphabetic characters. If you have front matter named with letter codes, they will come after file names that begin with numbers.
If the page images of an item should be ordered like this:
If they are named as in the list above, the WDL server will order the page images like this:
A correct file naming scheme to ensure proper ordering of these files would be:
Filenaming for Multi-Volume Items
Since the order of display is important, volumes should be named sequentially in the order in which the physical volume would be viewed (e.g., vol1, vol2, vol3). Each volume should exist in its own directory. The files within each directory should be named as indicated above.
Please let the WDL team know if you have questions about these guidelines or any other questions about how to prepare your files for delivery.