Why does Chrome use sec-ch-ua including "Not A Brand"?

[client-hints] GREASEing the Sec-CH-UA list

Randomizing order and string with escaped characters to ensure proper parsing and prevent ossification.

Source: user agent - Why does Chrome use sec-ch-ua: “"Not\A;Brand”;v=”99”? - Stack Overflow

That’s really interesting. It’s random and wrong on purpose.

Golang does something similar: randomize iteration order of small maps. Iteration is in a random order so that developers don’t depend on it always incrementing.