2.11 Hyperlink and cross-reference rules
Hyperlinks and cross-references point to items that appear in another location within a document or website. They can also be references to external documents or websites.
Cross-references can be typed manually. As you revise your document, however, there is a good chance that the pagination, section headings, figure numbers and so on will change, requiring you to update them all. To avoid this, all cross-references should be inserted as automated fields.