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DATE: December 20, 2013

NAME: Renaming and Redefining 347 $f (Transmission speed) in the MARC 21 Bibliographic Format

SOURCE: British Library

SUMMARY: This paper proposes renaming and redefining 347 $f to reflect the changes which have taken place in the equivalent RDA sub-element

KEYWORDS: Encoded bitrate (BD); Transmission speed (BD); Subfield $f, in Field 347 (BD); RDA

RELATED: 2011-08

12/20/13 – Made available to the MARC community for discussion.

01/26/14 – Results of MARC Advisory Committee discussion: Approved as submitted.

03/12/14 - Results of MARC Steering Group review - Agreed with the MAC decision.

Proposal No. 2014-03: Renaming and Redefining 347 $f (Transmission speed)


The 347 field (Digital file characteristics) was added to the MARC 21 Bibliographic format following Proposal 2011-08, which recommended that this be used to encode carrier characteristics specific to digital files in MARC. The 347 subfields $a to $f relate to equivalent sub-elements of the RDA element Digital file characteristics (RDA 3.19.)  The sub-element Transmission speed (RDA 3.19.7) was renamed Encoded bitrate as part of the July 2013 RDA update. The scope, sources and instructions associated with how this sub-element should be recorded were adjusted to accompany the change. To ensure that the appropriate name is used for the subfield, we suggest that the subfield name and definition are changed.


Current definition of Field 347 in the Bibliographic Format:

Current definition of subfield $f:

$f – Transmission speed
The speed at which streaming audio or video is designed to play.


347 ## $audio file$bMP3$f32 kbps$2rda

The RDA sub-element Transmission speed was renamed Encoded bitrate following analysis provided by Library of Congress that this term was a misnomer in the context of recorded data ( Transmission speed implies that data is being transmitted live. This is different from encoded bitrate, which is the data rate at which content is encoded. A live stream cannot be cataloged since it is, by definition, a live event and a record can only be created for a recording of that stream.

The scope of the RDA sub-element was also redefined because Library of Congress noted that there are more types of streamed content than audio and video. Most files produced now are pre-authored files, rather than those created from audio or video streaming.

The change proposed in the case of 347 $f relates to a subfield which was created as a direct result of RDA. Therefore, it seems reasonable that equivalence is maintained between the subfield label and that of the equivalent RDA sub-element. The same applies to their respective definitions. If this relationship were not so close, then the case for making changes may be less straightforward.


In BIBFRAME this type of name change could be handled in several ways, with more and less disruption to processes.  Transmission speed is not currently in the BIBFRAME vocabulary, but if it were, the property would probably be called transmissionSpeed and the URI for the property would probably use the property name as that is customary, e.g.,  The LABEL for that property would be "Transmission speed".  The URI can be changed but it would cause considerable disruption.  The LABEL can be more easily changed.


In the MARC 21 Bibliographic format:

4.1. Change the name of subfield $f in field 347 to Encoded bitrate.

4.2. Redefine the subfield to encompass all types of streamed content, not just audio and video, as follows:

$f – Encoded bitrate
The speed at which streaming audio, video, etc., is designed to play.

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