Final answer:
An example of a cross reference is a notation or hyperlink in a document that directs the reader to related information in another section or document, such as academic references, digital hyperlinks, or literary allusions.
Step-by-step explanation:
An example of a cross reference is a directional guide within a document that points the reader to another part of the same document or to another document altogether, where related information can be found. For instance, if an author mentions a topic earlier in a text and refers back to it in a later section, this is a cross reference. The notation 'See Example 3.1.3.1 for more information on David's project' would be a cross reference within an academic text. Similarly, in a digital format, hyperlinks serve as cross references, such as those marked with a red square leading to additional data or information as cited. In the context of literature, a cross reference can also be when a character in a play like Hamlet makes a reference to external works or ideas, such as Greek mythology figures, which are easily traceable for further exploration by the audience.