West publishes many reporters and digests, so it helps to have an understanding of the topic and key number system before you begin your research.
A key number consists of two parts: the topic (e.g., Divorce); and the key number itself (e.g., 309.2(2)).
In print, the topic and key number would appear as Divorce 309.2(2).
Online, there is much more information. You can access the Westlaw Key Numbers here.
These intermediate levels allow you to more specifically direct your search. A search on any intermediate level will bring up results for all the more specific levels below it.
When searching for a key number in print, you need the topic and the key number (e.g., Divorce 309.2(2)). However, online you replace the topic with its numerical equivalent (e.g., 134) and add it to the key number (e.g., 910(4)) separating the two with a "k." So the correct key number on Westlaw would be 134k910(4).
The same key number may appear under many topics, so you must use both the topic and key number to locate relevant information.