Joint MLA/OLAC 33X/34X Final Recommendations Redux

The final report summarizing the work of a joint MLA/OLAC task group which worked to address issues connected to 23 additions to the Genre/Form Code and Term Source Codes list (, which are utilized in the 33X and 34X fields, was issued in late 2017. The group was charged with examining three issues: inconsistent treatment of RDA and non-RDA terms in MARC 344 and 347, consideration of consistent treatment of MARC 344 and 347 across formats, and implementation of the new $2 source codes.

A question regarding the use of the new $2 source codes was recently raised. Just to be clear, the intent of the recommendation for issue 3 was that whenever separate MARC 34X fields would be required due to multiple applicable $2 source codes, to use separate MARC 34X fields – with the implication that the new source code would also be applied. The latter should have been more explicitly stated. After consultation with Bruce Evans, OLAC CAPC chair at the time and member of the task group, the recommendation for issue 3 has been amended to add the sentence: “Recommend use of new $2 source codes for MARC 34X fields.”

     We hope this amendment makes the intent of the group more clear, and clears up confusion over use of the $2 source codes. Catalogers should apply these recommendations, effective immediately. These recommendations will be incorporated into each group’s RDA best practices documents as future revisions are made. The entire document is available at the OLAC website:

The MLA RDA best practices will be updated in due course when the new Toolkit content is unfrozen. In the meantime, please feel free to use the following templates for encoding the 33X and 34X fields. Note that some subfields are marked “optional” – these subfields generally contain “standard” information for the format that was not originally recommended for encoding by the best practices. CSS will revisit the status of these optional subfields as part of the best practices revision process. Also note that some subfield values below will vary and only the most common values appear in the templates below.

Compact Disc

336  performed music $b prm $2 rdacontent

337  audio $b s $2 rdamedia

338  audio disc $b sd $2 rdacarrier

340  $b 4 3/4 in. (optional)

344  digital $2 rdatr

344  $b optical $2 rdarm

344  $g stereo $2 rdacpc

347  audio file $2 rdaft

347  $b CD audio

Vinyl Discs

336  performed music $b prm $2 rdacontent

337  audio $b s $2 rdamedia

338  audio disc $b sd $2 rdacarrier

340  vinyl $2 rdamat

340  $b 12 in. (optional)

344  analog $2 rdatr

344  $c 33 1/3 rpm 

344  $d microgroove $2 rdagw (optional for standard values)

344  $g stereo $2 rdacpc

Notated Music

336  notated music $b ntm $2 rdacontent

337  unmediated $b n $2 rdamedia

338  volume $b nc $2 rdacarrier

348  score $2 rdafnm