diff --git a/css/properties/position-area.json b/css/properties/position-area.json
index 4af14fc9bcc544..7a1b1ce626f672 100644
--- a/css/properties/position-area.json
+++ b/css/properties/position-area.json
@@ -51,7 +51,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `block-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -86,7 +88,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `block-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -121,7 +125,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `bottom` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -191,7 +197,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -226,7 +234,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `inline-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -261,7 +271,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `inline-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -296,7 +308,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `left` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -366,7 +380,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `right` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -398,7 +414,9 @@
             "spec_url": "https://drafts.csswg.org/css-anchor-position/#valdef-position-area-self-block-end",
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-block-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -429,7 +447,9 @@
             "spec_url": "https://drafts.csswg.org/css-anchor-position/#valdef-position-area-self-block-start",
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-block-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -463,7 +483,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -495,7 +517,9 @@
             "spec_url": "https://drafts.csswg.org/css-anchor-position/#valdef-position-area-self-inline-end",
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-inline-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -526,7 +550,9 @@
             "spec_url": "https://drafts.csswg.org/css-anchor-position/#valdef-position-area-self-inline-start",
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-inline-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -560,7 +586,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `self-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -595,7 +623,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "Using `span-all` unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1395,7 +1425,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `top` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1430,7 +1462,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `x-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1465,7 +1499,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `x-self-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1500,7 +1536,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `x-self-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1535,7 +1573,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `x-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1570,7 +1610,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `y-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1605,7 +1647,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `y-self-end` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1640,7 +1684,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `y-self-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",
@@ -1675,7 +1721,9 @@
             ],
             "support": {
               "chrome": {
-                "version_added": "129"
+                "version_added": "129",
+                "partial_implementation": true,
+                "notes": "When `y-start` is used as a single keyword, or alongside `span-all`, it unexpectedly allows the anchored box to overflow the viewport, obscuring content. Use `place-self: anchor-center` as a workaround. See [bug 438334710](https://crbug.com/438334710)."
               },
               "chrome_android": "mirror",
               "edge": "mirror",