Although I acknowledge Roy's points and agree with them. I do think the research on identifying what MARC fields and subfields have been used is necessary and beneficial for going forward, but I think the normative question of what data is useful is more interesting and important. Let me give a few examples of why I think this besides just format-specific usage. Some fields that show up a lot don't seem very useful. In my opinion, one of these is the 530 note, which says things like "Also available online" or "Also available on videocassette." If the other version is already in the catalog being searched, hopefully it should have already come up in whatever search was done. In the more likely case that it's not in the local catalog being searched, it confuses users, who often interpret the note to mean the other version is available to them. Presumably a system that did a better job of incorporating FRBR relationships would make this note obsolete anyway. On the other hand, there are some things that I think ought to be in MARC that aren't. I have devoted a lot of effort to trying to get some of these that are related moving image materials added. One that still isn't there is a consistent, machine-actionable place to unambiguously record the date of original release of a moving image in the bibliographic record. Original release date is generally given in citations for movies and TV programs so it's clear that it's important to users. Use can be unreliable for other reasons. For example, there is a chicken and egg problem with many data elements. Some of these are old elements which were prescient, but not used by systems. This led many catalogers to stop bothering with these fields despite their potential usefulness. As a former colleague put it, "I got tired of cataloging for my grandchildren." At my former library, we came up with a way to allow users to search for chamber music by instrumentation (http://www.bsu.edu/libraries/librarycatalogs/chambermusic.htm), but we had long ago stopped populating the 048 coded instrumentation fields that we needed to drive the searches. This left us with a lot of work to fill in the missing gaps in the data. A lot of newer fields and subfields don't seem to get a lot of use. It's partially because they are often niche elements, but it's also that they tend not to be supported by systems so they're not searchable in useful ways and they're often not publicized enough so that the broader community of catalogers know about them. This isn't necessarily a reflection of their potential value. Although application profiles may be a good solution for specialized data, there have to be the time and resources to set them up and maintain them. For smaller special interest groups, this may be difficult or impossible. As the OLAC liaison to CC:DA, I feel overwhelmed by the number of changes that we would like to see in the way moving images and other media materials are handled in RDA. OLAC is struggling with tackling this as well as creating best practice guidelines for RDA. It's hard for me to see that we have the resources for a major project on another front, such as an application profile for a new bibliographic framework. Kelley Kelley McGrath University of Oregon [log in to unmask]