In long technical documents, an index, or a list of almost everything in the document, is found at the end of the document. The index is a helpful tool for quickly locating information, and many readers expect it. There are several techniques for creating an index, but the most efficient and up to date is right at your fingertips. Microsoft Word allows you to create an index for a single word, a phrase, or even a symbol. You can also create an index item for a topic that covers several pages or paragraphs, or one that refers to another entry, such as "Chihuahua. See Dogs." After you have completed your document, consider what you think needs to be referenced in the index so the reader can find it quickly. You may need to brainstorm to make some decisions here, especially as to how detailed you want the index to be.
Race, Cassandra, "23. Help Desk: Creating an Index" (2016). Sexy Technical Communications. 23.