Judy, thanks for the historical background.
Now that LC has gone from tracing all new series to not tracing any series at all, the PCC has the opportunity to make new policy to carry on series authority control.
Rather than poring over those n's and t's which are really just an accident of history (the same series could have been traced or not, depending on whether it was established before or after 1989), how about just tracing all series that have authority records? These all have unique entries in the authority file, do they not? (I am away from the office and the usual reference works, so forgive me if I misremember). Series without authority records could still be tagged 490 0, if they did not seem to merit authority control.
Amy Turner, Duke University
Dear Ralph et al.,
Some historical background:
The use of "$5 DPCC" didn't begin until late in 1998 and it was only included in SARs being created for new series. Until then, a "$5 DLC" was often considered a "national-level" practice if other libraries wanted to use LC records in a copycat workstream without needing to check for consistency in presence/absence of series access points. Of course, any library can have any local practice it wants.
There was also a period of time in 1998 (and perhaps backwards into the end of 1997 - my memory fails me) when PCC participants were told to include a 645 $a t $5 DLC in new records (no $5 DLC for other treatment fields) to substitute for the national practice while we waited for MARC Development and National Standards Office to approve the "DPCC" code. Such a use of "DLC" was feasible because LC had changed its local practice to trace all new series as of 1989.