In the F# code formatting guidelines, I can find no descriptions of whether DU cases should have a space before a parenthesized argument:

let opt1 = Some ()
let opt2 = Some (1, 2)

or:

let opt1 = Some()
let opt2 = Some(1, 2)

Could this be clarified and added? I can add a PR, but let's find out what it should be first.