Char() function

Is the input for the Char() function Unicode or ASCII? Website documentation says ASCII but the Web app (version 8.2.0) says Unicode.

In my use case, I want to create a field that concatenates 'First Name', 'Last Name' and 'Number' on separate lines I've tried Char(9), Char(10), Char(11), Char(12) and Char(13) with no luck.