anchor.diff:  (:code "defun") ". If you want this command to be invocable outside of
           the context of a mode, use " (:code "define-command-global") ".")
       (:p "Example:")
  -    (:pre (:code
  -           "(define-command-global bookmark-url ()
  +    (:pre (:code "(define-command-global bookmark-url ()
     \"Query the user which URL to bookmark.\"
     (let ((url (prompt
                 :prompt \"Bookmark URL\"
  
positive.code:     (:p "To extend the bindings of a specific mode, you can extend the mode with "
          (:code "define-configuration") " and extend its binding scheme with "
          (:code "define-scheme") ". For example:")
      (:pre (:code "
  \(define-configuration base-mode
    ((keymap-scheme
      (define-scheme (:name-prefix \"my-base\" :import %slot-default%)
        scheme:vi-normal
  
negative.code:                                            :initform)))))
          ". "
          "The following example shows one way to add new search engines.")
      (:pre (:code "(defvar *my-search-engines*
    (list
     '(\"python3\" \"https://docs.python.org/3/search.html?q=~a\" \"https://docs.python.org/3\")\
     '(\"doi\" \"https://dx.doi.org/~a\" \"https://dx.doi.org/\")\)
  