just-the-docs/docs/tests/navigation/order/integers/index.md

layout	title	parent	nav_order	has_children
default	Integers	Tests for order	3	true

Integer Order

When nav_order fields are integers, the pages are ordered in increasing order of the numerical values.

Integers include 0 and negative values. Integers can be reused for top-level pages and for different sets of child pages.