It's just a separator page. Each of the parts is like that: https://abseil.io/resources/swe-book/html/part2.html https://abseil.io/resources/swe-book/html/part2

It's just a separator page. Each of the parts is like that: https://abseil.io/resources/swe-book/html/part2.html https://abseil.io/resources/swe-book/html/part2.html This is an html copy of a physical book. In book, that's nothing unusual.