It is not compulsory in RDA itself.  But for records contributed to the BIBCO and CONSER programs (that is, authenticated as PCC records), these guidelines must be applied.  So for an author, for a BIBCO record, recording the relationship designator is required.  If you aren't a BIBCO or CONSER library, you can just follow RDA as written, which makes all designators optional.  However, there are good arguments for including designators whenever possible, particularly for future bibliographic frameworks and systems which we hope will allow users to search and limit by particular roles such as author, editor, composer, etc.  For example if I want to find just works in which Leonard Bernstein was an author rather than a conductor, composer, or performer, having designators will make that possible.  Or films that Clint Eastwood both directed and acted in.  Without the designators, there's little 
possibility of doing these kinds of searches (granted, that for the Bernstein example you could probably limit to textual works (books), but that would still possibly get you books that he edited rather than authored if you don't have designators to work with.

Adam Schiff
University of Washington

On Wed, 27 Aug 2014, Annette Ingram wrote:

> Date: Wed, 27 Aug 2014 14:35:59 +0200
> From: Annette Ingram <[log in to unmask]>
> Reply-To: Program for Cooperative Cataloging <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: Relator codes
> 
> Dear Robert
>
> Thank you for your reply. Just one question. You say that if the MARC 1XX is not a creator, a relator designation is optional. But what if the 1XX is a creator (like the author of a book). Is the relator designation compulsory then?
>
> Regards.
> Annette
>
>>>> Robert Bratton <[log in to unmask]> 2014/08/27 02:16 PM >>>
> Hello Annette,
>
> Here are the PCC Guidelines for the Application of Relationship Designators
> in Bibliographic Records:
>
> http://www.loc.gov/aba/pcc/rda/PCC%20RDA%20guidelines/Relat-Desig-Guidelines-AUTH-Final.docx
>
> Two highlights"
>
> "Include a relationship designator for all creators, whether they are coded
> MARC 1XX or MARC 7XX.  If the MARC  1XX is not a creator, the addition of a
> relationship designator is optional though strongly encouraged.  Add a
> relationship designator even if the MARC field definition already implies a
> relationship.  Relationships should be coded explicitly and not inferred
> from MARC or other parts of the record.
>
> ...
>
> Guideline 9.  PCC highly encourages including relationship designators for
> all access points whenever it is clear what the relationship is."
>
> Robert
>
> --
>
> Robert Bratton
>
> Cataloging Librarian
>
> Jacob Burns Law Library
>
> George Washington University
>
> Washington, DC
>
>
> On Wed, Aug 27, 2014 at 5:24 AM, Annette Ingram <[log in to unmask]>
> wrote:
>
>> Dear colleagues
>>
>> We are implementing RDA original cataloguing soon and I would like to know
>> whether the usage of relator codes (#e) with authors, editors, corporate
>> bodies, etc. is mandatory in RDA? We feel that it is sometimes superfluous
>> (like #eauthor) but would not like to contravene mandatory RDA guidelines.
>> If it is mandatory, could I please have a reference to present to my
>> "critical" colleagues. I have been unsuccessful in finding a clear
>> guideline thus far.
>>
>> Thank you and kind regards.
>>
>> Annette Ingram (Cataloguer & trainer, University of Pretoria, Pretoria,
>> South Africa)
>>
>

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Adam L. Schiff
Principal Cataloger
University of Washington Libraries
Box 352900
Seattle, WA 98195-2900
(206) 543-8409
(206) 685-8782 fax
[log in to unmask]
http://faculty.washington.edu/~aschiff
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