I recently had the opportunity to use the One of operator on a CI validation of a registry integer value. While trying to input the multiple values (1, 3, 4 or 5) using a variety of delimiters (space, comma, semi-colon, etc.), I kept getting a UI error: "Invalid integer. Specify one value per line." The UI does not appear to provide the ability to enter multiple lines in the text control field, but I was able to copy/paste from Notepad and make it work. I later discovered that you can type the first value and then press CTRL + Enter to insert a new line for the next value. Once multiple lines are present, the scroll arrows on the text field are enabled. The Expression field will display the values with what appears to be a space between each, for example:
[TestSetting] One of 1 3 4 5
This should also hold true for the None of operator.