This just in from the Library of Congress Network Development and MARC Standards Office.
Changes to the Source Codes for Vocabularies, Rules, and Schemes.
“In making available changes to MARC to accommodate RDA, the Library of
Congress published lists of terms and codes for RDA content, media, and
carrier types. Upon further consideration we have determined that the
source codes do not adequately reflect the source material (RDA) as is
usually the case. Therefore, before the beginning of the RDA tests and
use of these codes, they have been changed to conform to the common
pattern. The new codes have replaced the ones formerly indicated in the
Source Codes for Vocabularies, Rules, and Schemes list for Genre/Form Term
and Code Sources. See the genre/form source code list for current usage in
MARC fields and MODS/MADS elements.”
The new codes may be used immediately for RDA records.
Genre/Form Term and Code Source Codes
The following source codes have been changed on the Genre/Form Code and
Term Source Codes list
rdacarrier (formerly marccarrier)
Term and code list for RDA carrier types
rdacontent (formerly marccontent)
Term and code list for RDA content types
rdamedia (formerly marcmedia)
Term and code list for RDA media types
The names of the respective value lists have also been changed to those
indicated above in order to reflect their content (see the listing of
value lists, Value Lists for Codes and Controlled Vocabularies).
The Library of Congress, Network Development and MARC Standards Office
provides information about existing and newly assigned source and value
codes on its web site.