• By contrast, a cross-reference knowl or an xref knowl is content that is a duplicate of some other content, in another location, as a result of an author making an <xref> cross-reference in their source. So a cross-reference in Chapter 8 to Example 4.6 will open the content of the example in the knowl, rather than transporting the reader backwards four chapters. If the reader does want to see the example in its original context in Chapter 4, then the knowl finishes with an in-context link that functions as a traditional hyperlink. Almost every cross-reference is a knowl, except when the target is a division—then a traditional hyperlink is used, since rendering an entire division as a knowl is unwieldy.
Note that some of these switches are for broad categories of items, for example, choosing to knowl theorems will also knowl <lemma>s, <corollary>s, <fact>s, and more. See Subsection 44.4.7 for precise details. This choice applies document-wide, there is no plan to support electing this on a case-by-case basis.