Word updating cross references
So if you have created headings, footnotes, page number, etc by yourself then you will not be able to cross-refer them.Now move the insert cursor where you want to insert Cross-Reference, click Cross-Reference in Captions group.By default, Word inserts a cross-reference as a hyperlink that you can click to be taken directly to the cross-referenced item.
To do that click on the text you want to reference and create a bookmark (Insert Cross-Reference, select "Bookmark" as the reference type and "Page number" under "Insert reference to".
If you add or remove content that causes the referenced item to move, you can update the cross-reference.
Do any of the following: Create a cross-reference You can insert cross references to any existing numbered items, headings, bookmarks, footnotes, endnotes, equations, figures, or tables in your document.
A cross-reference refers to an item that appears in another location in a document.
For example, you can mention "Figure 1" in your document and refer the reader to the figure's location elsewhere in the document.