diff --git a/notebook/assets/cookbook.css.implementing-numbered-headings/naive-tiered-headings.scss b/notebook/assets/code.recipes.css.implementing-numbered-headings/naive-tiered-headings.scss
similarity index 100%
rename from notebook/assets/cookbook.css.implementing-numbered-headings/naive-tiered-headings.scss
rename to notebook/assets/code.recipes.css.implementing-numbered-headings/naive-tiered-headings.scss
diff --git a/notebook/assets/cookbook.css.implementing-numbered-headings/optimized-tiered-headings.scss b/notebook/assets/code.recipes.css.implementing-numbered-headings/optimized-tiered-headings.scss
similarity index 100%
rename from notebook/assets/cookbook.css.implementing-numbered-headings/optimized-tiered-headings.scss
rename to notebook/assets/code.recipes.css.implementing-numbered-headings/optimized-tiered-headings.scss
diff --git a/notebook/cookbook.bash.percent-encoding.org b/notebook/code.recipes.bash.percent-encoding.org
similarity index 94%
rename from notebook/cookbook.bash.percent-encoding.org
rename to notebook/code.recipes.bash.percent-encoding.org
index 1b76cd5..df7ee94 100644
--- a/notebook/cookbook.bash.percent-encoding.org
+++ b/notebook/code.recipes.bash.percent-encoding.org
@@ -1,9 +1,9 @@
 :PROPERTIES:
 :ID:       8750a413-7cb8-4160-b4b3-3b54265b2825
 :END:
-#+title: Percent encoding in Bash
+#+title: Code recipes: Percent encoding in Bash
 #+date: "2021-06-23 21:10:33 +08:00"
-#+date_modified: "2022-04-16 20:17:53 +08:00"
+#+date_modified: "2022-10-25 10:38:40 +08:00"
 #+language: en
 
 
diff --git a/notebook/cookbook.css.implementing-numbered-headings.org b/notebook/code.recipes.css.implementing-numbered-headings.org
similarity index 90%
rename from notebook/cookbook.css.implementing-numbered-headings.org
rename to notebook/code.recipes.css.implementing-numbered-headings.org
index b8727ae..96a0f54 100644
--- a/notebook/cookbook.css.implementing-numbered-headings.org
+++ b/notebook/code.recipes.css.implementing-numbered-headings.org
@@ -1,13 +1,13 @@
 :PROPERTIES:
 :ID:       6d425762-ab9c-463f-b17a-e2a116b12fa0
 :END:
-#+title: Implementing tiered headings with CSS
+#+title: Code recipes: Implementing tiered headings with CSS
 #+date: "2021-06-20 10:31:00 +08:00"
-#+date_modified: "2021-06-20 18:16:24 +08:00"
+#+date_modified: "2022-10-25 17:05:19 +08:00"
 #+language: en
 
 
-You may have seen certain documents with [[https://practicaltypography.com/hierarchical-headings.html][tiered headings]].
+You may have seen certain documents with [[https://practicaltypography.com/hierarchical-headings.html][tiered headings]] especially in technical manuals and specifications (e.g., [[https://tc39.es/ecma262/][ECMAScript]], [[https://html.spec.whatwg.org/][HTML]]).
 To implement this with pure CSS, we'll make heavy use of [[https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Lists_and_Counters/Using_CSS_counters][CSS counters]].
 
 Here is one rough implementation with SCSS.
diff --git a/notebook/cookbook.hugo.base16-themes.org b/notebook/code.recipes.hugo.base16-themes.org
similarity index 94%
rename from notebook/cookbook.hugo.base16-themes.org
rename to notebook/code.recipes.hugo.base16-themes.org
index 6ce62d7..7aadcca 100644
--- a/notebook/cookbook.hugo.base16-themes.org
+++ b/notebook/code.recipes.hugo.base16-themes.org
@@ -1,9 +1,9 @@
 :PROPERTIES:
 :ID:       24df5797-6752-470d-89f5-517853573b3d
 :END:
-#+title: Implementing Base16 themes in Hugo
+#+title: Code recipes: Implementing Base16 themes in Hugo
 #+date: "2021-06-22 20:31:50 +08:00"
-#+date_modified: "2021-06-24 20:42:52 +08:00"
+#+date_modified: "2022-10-25 10:38:18 +08:00"
 #+language: en
 #+property: header-args  :eval no
 
diff --git a/notebook/recipes.hard-boiled-egg.org b/notebook/cooking.recipes.hard-boiled-egg.org
similarity index 100%
rename from notebook/recipes.hard-boiled-egg.org
rename to notebook/cooking.recipes.hard-boiled-egg.org
diff --git a/notebook/recipes.ice-scramble.org b/notebook/cooking.recipes.ice-scramble.org
similarity index 100%
rename from notebook/recipes.ice-scramble.org
rename to notebook/cooking.recipes.ice-scramble.org
diff --git a/notebook/recipes.shaved-ice.org b/notebook/cooking.recipes.shaved-ice.org
similarity index 100%
rename from notebook/recipes.shaved-ice.org
rename to notebook/cooking.recipes.shaved-ice.org