How does the Kindle decide whether to follow a link or display it as a footnote?

Question

I'm trying to debug a Kindle ebook that has both footnotes and internal navigation, on a Kindle e-ink reader. The problem is, some of the links that should take you to a different page are instead interpreted as footnotes showing up in a popup at the bottom of the page. How does the Kindle decide whether a link is for navigation or is a footnote? There's no attribute on the HTML <a> tags that would indicate each behavior.

Answer 1

According to the Kindle publishing guidelines,

To avoid unintended footnote pop-ups, internal links that are not footnotes should not be formatted with bidirectional hyperlinks (A links to B and B links to A) Non-footnote links should use the format A links to B and B links to C instead.