(define msg \#<<END "Hello, world!", she said. END )
is equivalent to
(define msg "\"Hello, world!\", she said.")
(define three 3) (display #<#EOF This is a simple string with an embedded `##' character and substituted expressions: (+ three 99) ==> #(+ three 99) (three is "#{three}") EOF )
prints
This is a simple string with an embedded `#' character and substituted expressions: (+ three 99) ==> 102 (three is "3")