Enable javascript on the swift docs, or you will see double asterisk (from markdown) in code snippets where the CODE is BOLD.

https://swift.org/documentation/api-design-guidelines/ in section: Parameters

func move(from **start**: Point, to **end**: Point)
is shown

func move(from start: Point, to end: Point)

is what you want to see

Note I could not figure out in a short amount of time how to make the example actually look like code, but so what :), you probably get the point. see link: https://meta.stackexchange.com/a/183611