diff --git a/css/definitions.json b/css/definitions.json
index 53ef5274..638dd782 100644
--- a/css/definitions.json
+++ b/css/definitions.json
@@ -5,7 +5,6 @@
       "Combinators",
       "Compositing and Blending",
       "CSS Anchor Positioning",
-      "CSS Angles",
       "CSS Animations",
       "CSS Backgrounds and Borders",
       "CSS Basic User Interface",
@@ -23,13 +22,11 @@
       "CSS Flexible Box Layout",
       "CSS Fonts",
       "CSS Fragmentation",
-      "CSS Frequencies",
       "CSS Generated Content",
       "CSS Grid Layout",
       "CSS Houdini",
       "CSS Images",
       "CSS Inline",
-      "CSS Lengths",
       "CSS Lists and Counters",
       "CSS Logical Properties and Values",
       "CSS Masking",
@@ -40,7 +37,7 @@
       "CSS Overflow",
       "CSS Overscroll Behavior",
       "CSS Paged Media",
-      "CSS Positioning",
+      "CSS Positioned Layout",
       "CSS Resolutions",
       "CSS Rhythmic Sizing",
       "CSS Ruby",
@@ -54,11 +51,9 @@
       "CSS Table",
       "CSS Text",
       "CSS Text Decoration",
-      "CSS Times",
       "CSS Transforms",
       "CSS Transitions",
       "CSS Types",
-      "CSS Units",
       "CSS Values and Units",
       "CSS View Transitions",
       "CSS Viewport",
diff --git a/css/functions.json b/css/functions.json
index d544f69c..2c798fd7 100644
--- a/css/functions.json
+++ b/css/functions.json
@@ -2,8 +2,7 @@
   "abs()": {
     "syntax": "abs( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/abs"
@@ -11,8 +10,7 @@
   "acos()": {
     "syntax": "acos( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/acos"
@@ -36,8 +34,7 @@
   "asin()": {
     "syntax": "asin( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/asin"
@@ -45,8 +42,7 @@
   "atan()": {
     "syntax": "atan( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/atan"
@@ -54,8 +50,7 @@
   "atan2()": {
     "syntax": "atan2( <calc-sum>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/atan2"
@@ -87,8 +82,7 @@
   "calc()": {
     "syntax": "calc( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/calc"
@@ -96,8 +90,7 @@
   "calc-size()": {
     "syntax": "calc-size( <calc-size-basis>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "experimental",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/calc-size"
@@ -113,8 +106,7 @@
   "clamp()": {
     "syntax": "clamp( <calc-sum>#{3} )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/clamp"
@@ -154,8 +146,7 @@
   "cos()": {
     "syntax": "cos( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/cos"
@@ -219,8 +210,7 @@
   "exp()": {
     "syntax": "exp( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/exp"
@@ -277,8 +267,7 @@
   "hypot()": {
     "syntax": "hypot( <calc-sum># )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/hypot"
@@ -365,8 +354,7 @@
   "log()": {
     "syntax": "log( <calc-sum>, <calc-sum>? )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/log"
@@ -390,8 +378,7 @@
   "max()": {
     "syntax": "max( <calc-sum># )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/max"
@@ -399,8 +386,7 @@
   "min()": {
     "syntax": "min( <calc-sum># )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/min"
@@ -408,8 +394,7 @@
   "minmax()": {
     "syntax": "minmax( [ <length-percentage> | min-content | max-content | auto ] , [ <length-percentage> | <flex> | min-content | max-content | auto ] )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/minmax"
@@ -417,8 +402,7 @@
   "mod()": {
     "syntax": "mod( <calc-sum>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/mod"
@@ -490,8 +474,7 @@
   "pow()": {
     "syntax": "pow( <calc-sum>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/pow"
@@ -523,8 +506,7 @@
   "rem()": {
     "syntax": "rem( <calc-sum>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/rem"
@@ -612,8 +594,7 @@
   "round()": {
     "syntax": "round( <rounding-strategy>?, <calc-sum>, <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/round"
@@ -685,8 +666,7 @@
   "sign()": {
     "syntax": "sign( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/sign"
@@ -694,8 +674,7 @@
   "sin()": {
     "syntax": "sin( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/sin"
@@ -727,8 +706,7 @@
   "sqrt()": {
     "syntax": "sqrt( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/sqrt"
@@ -744,8 +722,7 @@
   "tan()": {
     "syntax": "tan( <calc-sum> )",
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/tan"
diff --git a/css/properties.json b/css/properties.json
index 16fabd3d..8cef7739 100644
--- a/css/properties.json
+++ b/css/properties.json
@@ -3680,7 +3680,7 @@
     "animationType": "lpc",
     "percentages": "referToContainingBlockHeight",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -4002,7 +4002,7 @@
     "animationType": "discrete",
     "percentages": "no",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "none",
     "appliesto": "blockLevelElements",
@@ -4892,7 +4892,7 @@
     "animationType": "discrete",
     "percentages": "no",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "none",
     "appliesto": "allElementsNoEffectIfDisplayNone",
@@ -6132,7 +6132,8 @@
     "animationType": "lpc",
     "percentages": "logicalHeightOrWidthOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": [
       "top",
@@ -6158,7 +6159,8 @@
     "animationType": "lpc",
     "percentages": "logicalHeightOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": [
       "inset-block-start",
@@ -6180,7 +6182,8 @@
     "animationType": "lpc",
     "percentages": "logicalHeightOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -6196,7 +6199,8 @@
     "animationType": "lpc",
     "percentages": "logicalHeightOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -6212,7 +6216,8 @@
     "animationType": "lpc",
     "percentages": "logicalWidthOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": [
       "inset-inline-start",
@@ -6234,7 +6239,8 @@
     "animationType": "lpc",
     "percentages": "logicalWidthOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -6250,7 +6256,8 @@
     "animationType": "lpc",
     "percentages": "logicalWidthOfContainingBlock",
     "groups": [
-      "CSS Logical Properties and Values"
+      "CSS Logical Properties and Values",
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -6266,7 +6273,7 @@
     "animationType": "notAnimatable",
     "percentages": "no",
     "groups": [
-      "CSS Units"
+      "CSS Values and Units"
     ],
     "initial": "numeric-only",
     "appliesto": "allElements",
@@ -6362,7 +6369,7 @@
     "animationType": "lpc",
     "percentages": "referToWidthOfContainingBlock",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -7866,7 +7873,7 @@
     "animationType": "discreteButVisibleForDurationWhenAnimatedNone",
     "percentages": "no",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "none",
     "appliesto": "allElements",
@@ -8387,7 +8394,7 @@
     "animationType": "discrete",
     "percentages": "no",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "static",
     "appliesto": "allElements",
@@ -8576,7 +8583,7 @@
     "animationType": "lpc",
     "percentages": "referToWidthOfContainingBlock",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -10267,7 +10274,7 @@
     "animationType": "lpc",
     "percentages": "referToContainingBlockHeight",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
@@ -10846,7 +10853,7 @@
     "animationType": "integer",
     "percentages": "no",
     "groups": [
-      "CSS Positioning"
+      "CSS Positioned Layout"
     ],
     "initial": "auto",
     "appliesto": "positionedElements",
diff --git a/css/selectors.json b/css/selectors.json
index 2e307a8c..ba7e36e8 100644
--- a/css/selectors.json
+++ b/css/selectors.json
@@ -1031,7 +1031,8 @@
     "syntax": "::backdrop",
     "groups": [
       "Pseudo-elements",
-      "Selectors"
+      "Selectors",
+      "CSS Positioned Layout"
     ],
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/::backdrop"
diff --git a/css/selectors.md b/css/selectors.md
index 27aad3f9..85850a4e 100644
--- a/css/selectors.md
+++ b/css/selectors.md
@@ -21,7 +21,7 @@ A selector object looks like this:
 
 The three properties shown above are all required:
 * `syntax` (string): The syntax of the selector (e.g. `::after` with two colons indicating a [pseudo-element](https://developer.mozilla.org/en-US/docs/Learn/CSS/Introduction_to_CSS/Pseudo-classes_and_pseudo-elements#Pseudo-elements), `:hover` with one colon indicating a [pseudo-class](https://developer.mozilla.org/en-US/docs/Learn/CSS/Introduction_to_CSS/Pseudo-classes_and_pseudo-elements#Pseudo-classes), or `A ~ B` indicating a [combinator](https://developer.mozilla.org/en-US/docs/Learn/CSS/Introduction_to_CSS/Combinators_and_multiple_selectors#Combinators)).
-* `groups` (array of strings): CSS is organized in modules like "CSS Units" or "CSS Lengths". MDN organizes features in these groups as well — `groups` should contain the name of the module(s) the selector is defined in.
+* `groups` (array of strings): CSS is organized in modules like "CSS Values and Units". MDN organizes features in these groups as well — `groups` should contain the name of the module(s) the selector is defined in.
 * `status` (enum string): This is either `standard`, `nonstandard`, `experimental` or `obsolete` depending on the standardization status of the feature.
 
 There is another property that is optional:
diff --git a/css/units.json b/css/units.json
index cc4ad9da..7796d4bf 100644
--- a/css/units.json
+++ b/css/units.json
@@ -1,211 +1,183 @@
 {
   "cap": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "ch": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "cm": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "deg": {
     "groups": [
-      "CSS Units",
-      "CSS Angles"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "dpcm": {
     "groups": [
-      "CSS Units",
-      "CSS Resolutions"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "dpi": {
     "groups": [
-      "CSS Units",
-      "CSS Resolutions"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "dppx": {
     "groups": [
-      "CSS Units",
-      "CSS Resolutions"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "em": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "ex": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "fr": {
     "groups": [
-      "CSS Units",
+      "CSS Values and Units",
+      "CSS Flexible Box Layout",
       "CSS Grid Layout"
     ],
     "status": "standard"
   },
   "grad": {
     "groups": [
-      "CSS Units",
-      "CSS Angles"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "Hz": {
     "groups": [
-      "CSS Units",
-      "CSS Frequencies"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "ic": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "in": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "kHz": {
     "groups": [
-      "CSS Units",
-      "CSS Frequencies"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "mm": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "ms": {
     "groups": [
-      "CSS Units",
-      "CSS Times"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "pc": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "pt": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "px": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "Q": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "rad": {
     "groups": [
-      "CSS Units",
-      "CSS Angles"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "rem": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "s": {
     "groups": [
-      "CSS Units",
-      "CSS Times"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "turn": {
     "groups": [
-      "CSS Units",
-      "CSS Angles"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "vh": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "vmax": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "vmin": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "vw": {
     "groups": [
-      "CSS Units",
-      "CSS Lengths"
+      "CSS Values and Units"
     ],
     "status": "standard"
   },
   "x": {
     "groups": [
-      "CSS Units",
-      "CSS Resolutions"
+      "CSS Values and Units"
     ],
     "status": "standard"
   }
diff --git a/css/units.md b/css/units.md
index 77f59fa4..a73e64d4 100644
--- a/css/units.md
+++ b/css/units.md
@@ -13,13 +13,13 @@ A unit object looks like this:
 ```json
 "ch": {
   "groups": [
-    "CSS Units",
-    "CSS Lengths"
+    "CSS Values and Units"
   ],
   "status": "standard"
 }
 ```
 
 The 2 properties are both required.
-* `groups` (array of strings): CSS is organized in modules like "CSS Units" or "CSS Lengths". MDN organizes features in these groups as well — `groups` should contain the name of the module(s) the unit is defined in.
+
+* `groups` (array of strings): CSS is organized in modules like "CSS Values and Units". MDN organizes features in these groups as well — `groups` should contain the name of the module(s) the unit is defined in.
 * `status` (enum string): This is either `standard`, `nonstandard`, `experimental` or `obsolete` depending on the standardization status of the feature.