Removing General Material Designations from NLM Cataloging Records

Beginning with the implementation of Resource Description & Access (RDA) in April 2013 as the NLM cataloging guidelines, the National Library of Medicine (NLM) ceased adding the "General Material Designation" (GMD) to titles in our catalog. The GMD was a bracketed addition to the title that indicated the format for non-textual material.  In the MARC 21 format, the GMD is recorded in the 245 $h.

Example 1

Title:  Cerebrovascular diseases extra [electronic resource].

"electronic resource" is the GMD.

MARC view:

245 00 $a Cerebrovascular diseases extra $h [electronic resource].

Example 2

Title:  Active euthanasia [videorecording] : the introduction of the concept into Western medical thought / by W. Bruce Fye ; Health Communications Network, Medical University of South Carolina. 

"videorecording" is the GMD.

MARC view:

245 10 $a Active euthanasia $h [videorecording] : $b the introduction of the concept into Western medical thought / $c by W. Bruce Fye ; Health Communications Network, Medical University of South Carolina.

Current cataloging practice adds three fields to the record to replace the former GMD: Content Type (MARC 21 field 336), Media Type (MARC 21 field 337), and Carrier Type (MARC 21 field 338). These allow for more granular description of the format. To provide more consistent retrieval for users and make future data conversion simpler, NLM has decided to convert all the existing GMDs in the database to the equivalent 33X fields and remove the GMDs from the records. Because of the number of records involved, this project will be done over a period of time between Fall 2017 and Winter 2018.  The 33X fields will be added to records first, based on the existing GMD and other data in the record. Additionally, appropriate 33X fields will be added to all text records as well.  After all the records have had 33X fields added, the final step will be to remove the GMDs from every record in the database. During the transition period, users may encounter hybrid records that contain both a GMD and 33X fields.

Example 1 after update

Title:  Cerebrovascular diseases extra.

Content type: text

Media Type: computer

Carrier type: online resource

MARC view:

245 00 $a Cerebrovascular diseases extra.

336     $a text $b txt $2 rdacontent

337     $a computer $b c $2 rdamedia

338     $a online resource $b cr $2 rdacarrier

Example 2 after update

Title:  Active euthanasia : the introduction of the concept into Western medical thought / by W. Bruce Fye ; Health Communications Network, Medical University of South Carolina.

Content type: two-dimensional moving image

Media Type: video

Carrier type: videocassette

MARC view: 

245 10 $a Active euthanasia : $b the introduction of the concept into Western medical thought / $c by W. Bruce Fye ; Health Communications Network, Medical University of South Carolina.

336     $a two-dimensional moving image $b tdi $2 rdacontent

337     $a video $b v $2 rdamedia

338     $a videocassette $b vf $2 rdacarrier

After all the updates are completed, the revised records will be distributed to subscribers.  As the file set will be very large, NLM will provide early notifications before the records are distributed.