What if you want to classify a work on diet therapy for hypertension? Browsing the Relative Index for "hypertension" yields multiple entries, but none that mentions diet therapy. For a medical work, however, the following is of interest:
see also Cardiovascular diseases--humans
Following the see-also reference also leads to multiple entries, including the following:
Cardiovascular diseases--humans--diet therapy 616.1/0654
. . . . .
Cardiovascular diseases--humans--medicine 616.1
The number 616.10654 is too broad for a work on diet therapy for hypertension, but it is a clue that the correct number will be built with the base number for hypertension (616.132) plus 0654. Going back to the Relative Index browse display and clicking the entry for "Hypertension--medicine" leads to the full record display for 616.132 Hypertension, which includes the add footnote: "Add as instructed under 616.1-616.9."
The WebDewey number-building tool can help build a number that will be available the next time it is needed. In the record for 616.132 Hypertension,
(1) click START in the Create-built-number box;
(2) in the add table under 616.1-616.9 Specific diseases, look at 061-069 Specific therapies, note that the work does not belong in 061 Drug therapy, then click 062-069 Other therapies, where there is a note to "add to 06 the numbers following 615.8 in 615.82-615.89";
(3) in the Create-built-number box click ADD;
(4) browse the Relative Index for "diet therapy" and select the entry "Diet therapy--medicine," which leads to 615.854 Nutrition therapy, which has the class-here note "Class here diet therapy" and which falls within the span 615.82-615.89 named in the add note at 616.1-616.9:062-069 Other therapies;
(5) in the Create-built-number box click ADD.
Here is the result:
Click SAVE in the Create-built-number box. You can then use the number building engine to create a user term "Hypertension--diet therapy" that will display in the Relative Index. Detailed instructions for the WebDewey number-building tool are found on the Dewey Training Courses site.
An example of a work classed in 616.1320654 Hypertension--diet therapy is The DASH Diet for Hypertension: Lower Your Blood Pressure in 14 Days--without Drugs. It has the LCSH "Hypertension--Diet therapy."
What about cookbooks for diet therapy for hypertension--that is, the kind of work with the first LCSH "Hypertension--Diet therapy--Recipes"? Cookbooks are classed with cooking, in this case in 641.5631 Cooking for people with medical conditions, e.g., Hypertension Cookbook for Dummies and Delicious DASH Flavours: The Proven, Drug-Free, Doctor-Recommended Approach to Reducing High Blood Pressure. Works with a specific emphasis are classed with the emphasis, following the class-elsewhere note at 641.5631: "Class cooking for specific dietary regimens for specific medical conditions in 641.5632-641.5638." For example, Hold that Hidden Salt! Recipes for Delicious Alternatives to Processed, Salt-Heavy Supermarket Favourites has "Salt-free diet--Recipes" as its first LCSH and "Hypertension--Diet therapy--Recipes" as its second LCSH. The work is classed in 641.56323 Low-salt cooking, which has the class-here note: "Class here low-sodium cooking, salt-free cooking."