Change how to handle unevaluable source blocks

README.org

@@ -2149,8 +2149,7 @@ configuration objectives:
 :CUSTOM_ID: sec:writing-org-files
 :END:
 
-The [[https://org-babel.readthedocs.io/en/latest/][Org Babel reference card]] complements section [[info:org#Working with Source Code][Working with Source Code (info)]]
-of the [[info:org#Top][Org (info)]] manual. Here are links to Org-mode videos:
+Here are links to Org-mode videos:
 1. [[yt:o6rE18Mxu9U][Analyze Your Time with Org Mode Clocktables]]
 2. [[yt:EgOBBiomfGo][Basic Task Management with Org: Checklists, TODOs, and Org-Agenda]]
 3. [[yt:oJTwQvgfgMM][Emacs Org-mode: a system for note-taking and project planning]]
@@ -2169,9 +2168,7 @@ of the [[info:org#Top][Org (info)]] manual. Here are links to Org-mode videos:
 (with-eval-after-load 'emacs
   (global-set-key (kbd "C-c a") #'org-agenda)
   (global-set-key (kbd "C-c c") #'org-capture)
-  (with-eval-after-load 'ol
-    (global-set-key (kbd "C-c l") #'org-store-link)
-    (global-set-key (kbd "C-c C-l") #'org-insert-link-global)))
+  (global-set-key (kbd "C-c l") #'org-store-link))
 #+end_src
 
 *** Setup Org
@@ -2186,9 +2183,9 @@ list detailing and motivating each listing:
    more information.
 3. Listing [[lst:setup-org-babel]] sets ~ob-core~, ~ob-latex~, and ~ob-lisp~ options.
    See [[info:org#Working with Source Code][working with source code (info)]] for Org Babel information.
-4. Listing [[lst:fake-org-babel-functions]] adds =org-babel-execute:<LANGUAGE>=
-   functions to silence src_emacs-lisp[:results silent]{(find-library
-   "org-lint")}.
+4. Listing [[lst:no-org-babel-eval]] prevents evaluation of blocks without an
+ =org-babel-execute:<LANG>= function and adds fake =org-babel-execute:<LANG>=
+   functions to silence {{{kbd(M-x org-lint)}}} warnings.
 5. Listing [[lst:set-org-link-options]] handles [[https://orgmode.org/][Org-mode]] options specific to
    [[info:org#Hyperlinks][hyperlinks (info)]].
 6. Listing [[lst:looking-at-org-id]] enables recent ~org-id~ features.
@@ -2305,22 +2302,24 @@ Watch out for completion `visit-tags-table' prompts."
     (setopt org-babel-lisp-eval-fn #'sly-eval)))
 #+end_src
 
-#+caption[Fake =org-babel= functions]:
-#+caption: Fake =org-babel= functions.
-#+name: lst:fake-org-babel-functions
+#+caption[Unevaluable source blocks]:
+#+caption: Unevaluable source blocks.
+#+name: lst:no-org-babel-eval
 #+begin_src emacs-lisp -n :results silent
-;; Modes are not executable:
+(setq org-babel-default-header-args:conf '((:eval . "no")))
+(setq org-babel-default-header-args:diff '((:eval . "no")))
+(setq org-babel-default-header-args:text '((:eval . "no")))
+(setq org-babel-default-header-args:toml '((:eval . "no")))
+
+;;; Kludges to silence `org-lint' warnings:
 (defun org-babel-execute:conf (_body _params)
-  "NO-OP to silence warnings." nil)
-
+  "Silence `org-lint' warnings." nil)
 (defun org-babel-execute:diff (_body _params)
-  "NO-OP to silence warnings." nil)
-
+  "Silence `org-lint' warnings." nil)
 (defun org-babel-execute:text (_body _params)
-  "NO-OP to silence warnings." nil)
-
+  "Silence `org-lint' warnings." nil)
 (defun org-babel-execute:toml (_body _params)
-  "NO-OP to silence warnings." nil)
+  "Silence `org-lint' warnings." nil)
 #+end_src
 
 #+caption[Set =org-link= options]:
@@ -2405,7 +2404,8 @@ When called twice, replace the previously inserted \\(\\) by one $."
   ;; Stolen from `org-insert-structure-template'.
   ;; Note: `org-tempo' does not require `tempo' at all.
   (defcustom org-insert-source-block-defaults
-    '("emacs-lisp -n :results silent"
+    '("calc -n :results silent"
+      "emacs-lisp -n :results silent"
       "julia -n :results silent"
       "latex -n"
       "lisp -n :results silent :package :cs325-user"