1) The update includes agreements between PCC and LC with regard to "best practices" in the new MARC fields for authority records.
Note especially the information on the use of subfields $u and $v; the full text on the use of $u and $v is supplied only in the 046 section, but it is referenced in each of the fields where these subfields may be used.
Here is an excerpt from that 046 section on the use of subfields $u and $v -- NACO catalogers please take note:
The following represents PCC practice on recording sources of information in $u and $v in fields where they are defined, and/or in field 670:
1. 670s must be used to support information used as part of a heading in 1XX and 4XX.
2. For 046, 37X, 381:
a. use of $v is optional if the same information/source is already cited in the 670
b. use $v if the information/source is not cited in a 670
c. use of $u is optional, and should always be preceded by $v.
2) Catalogers are instructed to no longer supply Content Type information in the 336 field of authority records, pending the outcome of report/recommendations from the PCC Access Point for Expressions Task Group. Please see the 336 section.
3) Very exciting: New information on 4XX references in the 4XX section. Here is an excerpt:
Best practice guidelines for RDA:
• Record variants found in the manifestation being cataloged:
° Use cataloger's judgment;
° No limitation on the number or form of references
• Establish additional headings needed to support elements used in 4XX references (e.g. parent body associated with subordinate body being established)
• Trace a former heading as a cross-reference in all cases, unless the former heading was egregiously incorrect
• Use the established form of components in 4XX references, except for non-Latin script references
• If a form found on the manifestation being cataloged includes a variant form of a component of a 4XX reference, that form may be used in its entirety as an additional 4XX reference, provided that it is not divided into its component parts through the use of subfields.
4) The recently announced MARC change in field 368 is not reflected in the DCM Z1 update, but will be changed with the next update; however, please do not use the newly defined subfields in 368 until LC-PCC announces that these are ready for use.
(Source: By Paul Frank through PCC LIST)