diff --git a/bundle/bundle--mk.el b/bundle/bundle--mk.el
index 6a6aef22..8c65928b 100644
--- a/bundle/bundle--mk.el
+++ b/bundle/bundle--mk.el
@@ -61,5 +61,20 @@
 ;;     (add-hook 'after-init-hook (lambda () (org-agenda-list) (me/split-h3)))
 ;;   (org-agenda-list))
 
+(defvar mk/useful-websites
+  '(("https://regexr.com/" regex debug)
+    ("https://regex101.com/" regex debug)
+    ("https://www.regextester.com/" regex debug)
+    ("https://extendsclass.com/regex-tester.html#python" regex debug)))
+
 (defvar mk/mirror-website
   "Locally mirror a website using `wget -mkEpnp <ur>`")
+
+(defvar mk/useful-regex
+  '(("[\w\s]+:" "match any word or space that precede the :")
+    ("\[.*\]" "search for anything in square brackets")
+    ("[A-Za-z]+" "upper and lowercase english alphabet")
+    ("[0-9]" "numbers from 0 to 9")
+    ("[A-Za-z\-\.]" "upper and lowercase english alphabet, - and .")
+    ("(a-z)" "a, - and z")
+    ("(\s+|,)" "spaces or a comma")))