Should you use international identifiers in Java/C#?

Question

C# and Java allow almost any character in class names, method names, local variables, etc.. Is it bad practice to use non-ASCII characters, testing the boundaries of poor e

Answer 1

Here's an example of where I've used non-ASCII identifiers, because I found it more readable than replacing the greek letters with their English names. Even though I don't have θ or φ on my keyboard (I relied on copy-and-paste.)

However these are all local variables. I would keep non-ASCII identifiers out of public interfaces.