What’s in a note? Part 1

Most notes in the DDC do a pretty good job of getting across their intent in plain English (or in the language of your chosen translation). If you’re classifying a work on a given topic and find the topic in a note that says “class here” or “including”, you know you’re in the right place. If you see it in a note that refers you to a different number, you know you should head over there. A note by any other wording would do just as well, right? Not exactly. By minding the wording of a note in addition to just looking for the topics, you can get some valuable information about how to classify.

This is the first in a two-part series about some of the different types of notes that may initially sound like they’re saying the same thing, but actually have some important differences. First, I’ll compare the notes that tell you you’re in the right place (class-here and including), and the next will cover notes that point elsewhere.

A topic in a class-here note is said to approximate the whole of the class number. That doesn’t mean it’s identical, but it’s close enough that we probably won’t give that topic its own number in the future. For example, the caption at 597 is “Cold-blooded vertebrates”. Since reptiles and amphibians have their own numbers underneath, that mostly leaves fishes. Most of the numbers under 597 are about fish, except for those dedicated to reptiles and amphibians. We will probably never continue fishes and have separate numbers for fishes and (all) cold-blooded vertebrates.

You can add standard subdivisions for any topic in a class-here note, so 597.03 is equally valid for an encyclopedia of fishes or an encyclopedia of cold-blooded vertebrates. Class-here notes have hierarchical force, meaning they apply at the number where they’re given and all of its subdivisions. Another topic in the class-here note at 597 is “bony fishes”, which describes the vast majority of all living fish species. So an encyclopedia of bony fishes could also class at 597.03, and even as you go further down in 597, you don’t need to distinguish between cold-blooded vertebrates, fishes, and bony fishes.

What about including notes, then? Topics there still class at the number where the note appears, but they are topics in standing room; they do not approximate the whole. For example, let’s look at 595.387 Anomura. Anomura is a taxonomic group of crustaceans. Among other animals, hermit crabs are part of Anomura. But in the DDC, hermit crabs are in an including note there. Because they don’t approximate the whole, standard subdivisions cannot be added for hermit crabs. A zoological journal dedicated to Anomura would class at 595.38705, but a journal dedicated to hermit crabs would just be 595.387, with no standard subdivision.

There are two main reasons why we would put a topic in an including note—and sometimes it’s both:

1. The topic is just one smaller part of what’s in the class. Using the example of 595.387, there are many Anomura species that are not hermit crabs.
2. There were not enough works about the topic when we last checked (what we call literary warrant).

It’s important to note the part about “when we last checked”. If you ever come across a topic in standing room that seems like it obviously deserves its own number, you may well be right! Sounds like a great opportunity to contact us and get involved in the editorial process yourself! (See oc.lc/DeweyContributors for more information.)

I hope this has been helpful in explaining the difference between two notes that seem to do the same thing, but still signal important differences. Stay tuned for the next post on see references, class-elsewhere notes, and see-also notes.