Naming convention for born-digital media

Create a batch number with the base call number (minus the "MS") plus "BD" for born-digital.

The case number for the entire batch of the Updike born-digital material would be:

                              Am1793BD

For each physical item of media, the item number will be the batch number followed by an underscore and the sequential number.

For instance, the 9^th disk of 41 imaged in the John Updike collection would be given this evidence number:

                              Am1793_BD09