[racket] help on understanding abort-current-continuation at the toplevel module level

I'm trying to find information on what the default handler is, for the
prompts established at the toplevel of a module.  From the following
program:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#lang racket/base

1
(call-with-continuation-prompt
 (lambda ()
   (abort-current-continuation (default-continuation-prompt-tag)
                               (lambda () (printf "hello\n")))))

2

(abort-current-continuation (default-continuation-prompt-tag)
                            (lambda () (printf "world\n")))

3
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

I was expecting each statement to be wrapped in a prompt whose handler
re-establishes the prompt and calls the thunk, that is, I was
expecting the implicit handler:

    (lambda (abort-thunk)
       (call-with-continuation-prompt abort-thunk prompt-tag #f))

wrapped around each toplevel module expression, and that I'd see
"1hello\n2world\n3".  But as usual, I'm wrong.  :)

Where in the documentation can I find the behavior of the prompt
handler that's wrapped around each module toplevel expression?