Ask HN: What are some examples of well-designed binary file format specs?

This is my first time working with binary data, binary specifications, etc., and I've started to mess around with the dBASE file format [0] after reading about it in NodeJS in Practice [1]. I know about the usual ones (e.g., PNG, JPEG, etc) at least by name and I'm now wondering about what's out there, especially less well-known formats or niche ones.

0: https://en.wikipedia.org/wiki/.dbf

1: https://www.manning.com/books/node-js-in-practice