Today we have an unusual code golf: build a program (using only printable ASCII characters, tabs and newlines) that prints out exactly the characters in the printable ASCII space (characters 32 to 126) that don't appear in your program's source code (in any order, however many times you want).
As usual, the goal is to produce the shortest code to do this.
My (admittedly not very good, but does the job!) entry: