Finding the Appropriate Class Number
Primary Subject(s) Not in Classification Index
When the MeSH term is not listed in the NLM Classification Index, locate the broader term under which the primary MeSH term is treed in the MeSH Browser and use that class number.
Example
The MeSH term "Iris Neoplasms" is not in the NLM Classification Index. Using the MeSH Browser, we can see it is treed under "Uveal Neoplasms." The NLM Classification Index has "Uveal Neoplasms" classed at WW 240. "Iris Neoplasms" would also be classed at WW 240.
Using the Scope Note
Sometimes there are complex situations where a term is treed in more than one place. For example, "Pandemic Preparedness" is treed in two places: Disaster Planning (WX 186) and Communicable Disease Control (WA 295). The cataloger must decide where to class this based on the emphasis of the work.
In the MeSH Browser, read the MeSH scope note, annotation, and previous indexing field for the chosen term and for that of the next higher terms in the tree. Determine the context in which the term is used in the item being cataloged (i.e., determine the primary focus).
Example
The MeSH term "Auriculotherapy" is not in the NLM Classification Index. Although it trees under "Complementary Therapies" (WB 880–962), per the scope note and previous indexing, it is closely associated with "Ear Acupuncture" (WB 369.5.E2) and should be classed there.
