See Prefix Command Arguments . The numeric prefix argument. The raw prefix argument. This is the only code letter that specifies two successive arguments rather than one. S An interned symbol whose name is read in the minibuffer.
Any whitespace character terminates the input.
See High-Level Completion . Existing, Completion, Prompt. The object is not evaluated. See Object from Minibuffer . Lisp form is read as with x , but then evaluated so that its value becomes the argument for the command.