I chuckled because when I see <quote> I made a mistake quoting a symbolic entity in an x-expression, e.g.:

#lang racket/base
(require xml)
(xexpr->string '(p "yay" nbsp  "yay")) ;=> "<p>yay yay</p>"
(xexpr->string '(p "boo" 'nbsp "boo")) ;=> "<p>boo<quote> </quote>boo</p>"

(The other ingredient is the Racket reader expands 'thing to (quote thing).)

To be honest I made the same mistake before I post the question here X )