When I was fairly young, professionally speaking, I ran the corporate/research library for Masonite Corporation. This was, then, a Fortune 500 company and was a big name in the forest products business.
(The company’s been bought a couple times since then and filed for bankruptcy, but you can still see its logo on a few products.)
This was among my happiest experiences as a librarian inasmuch as I was working for people who appreciated my services … but not enough to avoid being laid off along with 1/3 of the R&D staff in early 1982. Masonite is where I was first exposed to online database searching, at 300 baud. It is where I wrote a database thesaurus. It was also where I became familiar with non-Library of Congress Subject Headings.
You see, when you’re running a specialized library the LC headings are insufficient. Your users need more detail, especially when they are on the “cutting edge” and are actually inventing the terminology as they go along.
This was, sort-of, what we’d call “tagging” today. I was doing some of this as well since I had been given the responsibility of re-reading and indexing all of the research reports going back to the late 1920s. Some items just didn’t fit the terminology in general use in the early 80s.
I relied upon two sources to help my “humanities trained” mind wrestle with what chemists and wood technologists were reporting. These were subject thesauri from The Institute of Paper Chemistry and from the Forest Products Research Society.
I mention this because it is important for beginning reference librarians to understand that there are subject headings beyond what LC can provide. It is important in a time when users are able to put their own tags in the library catalog. It is critical when reference staff need to tag the online resources they use … especially as “the semantic web” seems to have flat-lined from a predictable lack of interest.
I suggest that one thing reference librarians going for a master’s degree might do is create a thesaurus for some smallish field-of-knowledge. Perhaps covering a small town’s history or a hobby. Those going for a doctorate might do so for something larger, such as a state’s history or an academic discipline.
I also suggest that one focus for the “reference profession” is the maintenance (and curation) of such thesauri at some public web-accessible place for their use by people wanting to tag the documents and sites they think need tagging. This way, such tagging might be usable for more than just a decade or so (if that!) … and feedback would help the profession keep tabs on the ever growing, evolving, use of language.