> but since there is really no standard field for such a value, anything I
choose is all but arbitrary. I’ll use some 9xx field, just to make things
easy. I can always (and easily) change it later.

More like there are SEVERAL standard fields for such a value.

You can certainly put it in one of the existing standard fields, you just
have to actually follow the (often byzantine legacy) rules for such entry.
For instance, the date you want may very well already be in the fixed field
008, and you could certainly add it if it weren't. But the rules and
practices for 008 are confusing -- in part, because the actual real world
universe of "what is the date of this thing" is itself complex in the real
world of actually cataloged things, including serials and series,
manuscripts, reprints and fascimiles, old things where we aren't sure of
the exact dates, etc.  And in part just because the MARC standard is kind
of old and creaky, especially with regard to fixed fields like 008 being
designed to cram maximum amount of information in minimum bytes, beyond any
reasonable economy actually needed today.

I just learned about the 264 from Karen Miller's post (thanks Karen), I
dunno about that one, but it looks like it might be applicable too.

Standards, why have just one when you can have a dozen?

On Tue, Jul 12, 2016 at 10:12 AM, Eric Lease Morgan <[log in to unmask]> wrote:

> On Jul 11, 2016, at 4:32 PM, Kyle Banerjee <[log in to unmask]>
> wrote:
>
> >>
> https://github.com/traject/traject/blob/e98fe35f504a2a519412cd28fdd97dc514b603c6/lib/traject/macros/marc21_semantics.rb#L299-L379
> >
> > Is the idea that this new field would be stored as MARC in the system
> (the
> > ILS?).
> >
> > If so, the 9xx solution already suggested is probably the way to go if
> the
> > 008 route suggested earlier won't work for you. Otherwise, you run a risk
> > that some form of record maintenance will blow out all your changes.
> >
> > The actual use case you have in mind makes a big difference in what paths
> > make sense, so more detail might be helpful.
>
>
> Thank you, one & all, for the input & feedback. After thinking about it
> for a while, I believe I will save my normalized dates in a local (9xx)
> field of some sort.
>
> My use case? As a part of the "Catholic Portal", I aggregate many
> different types of metadata and essentially create a union catalog of rare
> and infrequently held materials of a Catholic nature. [1] In an effort to
> measure “rarity” I've counted and tabulated the frequency of a given title
> in WorldCat. I now want to measure the age of the materials in the
> collection. To do that I need to normalize dates and evaluate them. Ideally
> I would save the normalized dates back in MARC and give the MARC back to
> Portal members libraries, but since there is really no standard field for
> such a value, anything I choose is all but arbitrary. I’ll use some 9xx
> field, just to make things easy. I can always (and easily) change it later.
>
> [1] "Catholic Portal” - http://www.catholicresearch.net
>
> —
> Eric Lease Morgan
>