diff --git a/css/css-scoping/has-slotted-001.tentative.html b/css/css-scoping/has-slotted-001.tentative.html
index 9a9563287631b6..e750d97a180b5d 100644
--- a/css/css-scoping/has-slotted-001.tentative.html
+++ b/css/css-scoping/has-slotted-001.tentative.html
@@ -1,6 +1,6 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(*)</title>
+<title>:has-slotted</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
@@ -13,11 +13,10 @@
           height: 100px;
           background-color: red;
         }
-        :has-slotted(*) {
+        :has-slotted {
           background-color: green;
         }
       </style>
       <slot></slot>
     </template>
-    <div></div>
 </div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-002.tentative.html b/css/css-scoping/has-slotted-002.tentative.html
index 40b4edb3841684..729f105719b98a 100644
--- a/css/css-scoping/has-slotted-002.tentative.html
+++ b/css/css-scoping/has-slotted-002.tentative.html
@@ -1,6 +1,6 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(...) negative test: no children or white space</title>
+<title>:has-slotted negative test: no children or white space</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
@@ -12,7 +12,6 @@
         height: 100px;
         background-color: green;
     }
-    :has-slotted(*),
     :has-slotted {
         background-color: red;
     }
diff --git a/css/css-scoping/has-slotted-003.tentative.html b/css/css-scoping/has-slotted-003.tentative.html
index 9565b1594c3ed7..7578413ff39770 100644
--- a/css/css-scoping/has-slotted-003.tentative.html
+++ b/css/css-scoping/has-slotted-003.tentative.html
@@ -1,22 +1,23 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(...) negative test: no children, but whitespace present</title>
+<title>:has-slotted</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
 <div id="host">
     <template shadowrootmode="open">
-        <style>
+      <style>
         slot {
-            display: block;
-            width: 100px;
-            height: 100px;
-            background-color: green;
+          display: block;
+          width: 100px;
+          height: 100px;
+          background-color: red;
         }
-        :has-slotted(*) {
-            background-color: red;
+        :has-slotted {
+          background-color: green;
         }
-        </style>
-        <slot></slot>
+      </style>
+      <slot></slot>
     </template>
+    <div></div>
 </div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-changing-001.tentative.html b/css/css-scoping/has-slotted-changing-001.tentative.html
new file mode 100644
index 00000000000000..f4c99cdb5dcc2c
--- /dev/null
+++ b/css/css-scoping/has-slotted-changing-001.tentative.html
@@ -0,0 +1,59 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted through a single shadow root</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+  <div id="test"><template shadowrootmode="open">
+    <slot></slot>
+    <p id="target">This text will be styled.</p>
+    <style>
+      p {
+        color: rgb(0 255 0);
+      }
+      slot:not(:has-slotted) + p {
+        color: rgb(0 0 255);
+      }
+    </style>
+  </template></div>
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    test(function () {
+      const test = document.getElementById('test');
+      const target = test.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = ' ';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.replaceChildren();;
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const div = document.createElement('div');
+      test.append(div);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      const node = document.createTextNode(' ');
+      test.replaceChildren(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.innerHTML = '';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-changing-002.tentative.html b/css/css-scoping/has-slotted-changing-002.tentative.html
new file mode 100644
index 00000000000000..98ad6019ab021d
--- /dev/null
+++ b/css/css-scoping/has-slotted-changing-002.tentative.html
@@ -0,0 +1,60 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted through multiple shadow roots</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+  <div id="test"><template shadowrootmode="open"><div id="inner"><template shadowrootmode="open">
+    <slot></slot>
+    <p id="target">This text will be styled.</p>
+    <style>
+      p {
+        color: rgb(0 255 0);
+      }
+      slot:not(:has-slotted) + p {
+        color: rgb(0 0 255);
+      }
+    </style>
+  </template><slot></slot></div></template></div>
+
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    test(function () {
+      const test = document.getElementById('test');
+      const inner = test.shadowRoot.getElementById('inner');
+      const target = inner.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const node = document.createTextNode(' ');
+      test.replaceChildren(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      node.remove();
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = '<div></div>';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.appendChild(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.textContent = '';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-flattened-001.tentative.html b/css/css-scoping/has-slotted-flattened-001.tentative.html
index f14bdbc776d639..0235f99e21f1c9 100644
--- a/css/css-scoping/has-slotted-flattened-001.tentative.html
+++ b/css/css-scoping/has-slotted-flattened-001.tentative.html
@@ -1,28 +1,24 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(*) flattened through multiple slots</title>
+<title>:has-slotted flattened through multiple slots</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
 <div id="ancestor">
     <template shadowrootmode="open">
-        <div id="host">
-            <template shadowrootmode="open">
-              <style>
-                slot {
-                  display: block;
-                  width: 100px;
-                  height: 100px;
-                  background-color: red;
-                }
-                :has-slotted(*) {
-                  background-color: green;
-                }
-              </style>
-              <slot></slot>
-            </template>
+        <div id="host"><template shadowrootmode="open">
+            <style>
+            slot {
+                display: block;
+                width: 100px;
+                height: 100px;
+                background-color: red;
+            }
+            :has-slotted {
+                background-color: green;
+            }
+            </style>
             <slot></slot>
-        </div>
+        </template><slot></slot></div>
     </template>
-    <div></div>
 </div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-flattened-002.tentative.html b/css/css-scoping/has-slotted-flattened-002.tentative.html
index f72ff1de5aa298..bc14cad643ddd7 100644
--- a/css/css-scoping/has-slotted-flattened-002.tentative.html
+++ b/css/css-scoping/has-slotted-flattened-002.tentative.html
@@ -1,6 +1,6 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(...) negative test: no children or white space</title>
+<title>:has-slotted negative test: no children or white space</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
@@ -13,7 +13,6 @@
             height: 100px;
             background-color: green;
         }
-        :has-slotted(*),
         :has-slotted {
             background-color: red;
         }
diff --git a/css/css-scoping/has-slotted-flattened-003.tentative.html b/css/css-scoping/has-slotted-flattened-003.tentative.html
index bca81b971de20d..5f007fbd1b0fb4 100644
--- a/css/css-scoping/has-slotted-flattened-003.tentative.html
+++ b/css/css-scoping/has-slotted-flattened-003.tentative.html
@@ -1,27 +1,25 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted(...) flattened through multiple slots, negative test: no children, but whitespace present</title>
+<title>:has-slotted flattened through multiple slots</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
 <div id="ancestor">
     <template shadowrootmode="open">
-        <div id="host">
-            <template shadowrootmode="open">
-                <style>
-                slot {
-                    display: block;
-                    width: 100px;
-                    height: 100px;
-                    background-color: green;
-                }
-                :has-slotted(*) {
-                    background-color: red;
-                }
-                </style>
-                <slot></slot>
-            </template>
-        </div>
-        <slot></slot>
+        <div id="host"><template shadowrootmode="open">
+            <style>
+            slot {
+                display: block;
+                width: 100px;
+                height: 100px;
+                background-color: red;
+            }
+            :has-slotted {
+                background-color: green;
+            }
+            </style>
+            <slot></slot>
+        </template><slot></slot></div>
     </template>
+    <div></div>
 </div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-flattened-007.tentative.html b/css/css-scoping/has-slotted-flattened-007.tentative.html
deleted file mode 100644
index 0235f99e21f1c9..00000000000000
--- a/css/css-scoping/has-slotted-flattened-007.tentative.html
+++ /dev/null
@@ -1,24 +0,0 @@
-<!doctype html>
-<meta charset="utf-8">
-<title>:has-slotted flattened through multiple slots</title>
-<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
-<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
-<p>Test passes if there is a filled green square.</p>
-<div id="ancestor">
-    <template shadowrootmode="open">
-        <div id="host"><template shadowrootmode="open">
-            <style>
-            slot {
-                display: block;
-                width: 100px;
-                height: 100px;
-                background-color: red;
-            }
-            :has-slotted {
-                background-color: green;
-            }
-            </style>
-            <slot></slot>
-        </template><slot></slot></div>
-    </template>
-</div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-007.tentative.html b/css/css-scoping/has-slotted-functional-001.tentative.html
similarity index 88%
rename from css/css-scoping/has-slotted-007.tentative.html
rename to css/css-scoping/has-slotted-functional-001.tentative.html
index e750d97a180b5d..9a9563287631b6 100644
--- a/css/css-scoping/has-slotted-007.tentative.html
+++ b/css/css-scoping/has-slotted-functional-001.tentative.html
@@ -1,6 +1,6 @@
 <!doctype html>
 <meta charset="utf-8">
-<title>:has-slotted</title>
+<title>:has-slotted(*)</title>
 <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
 <link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
 <p>Test passes if there is a filled green square.</p>
@@ -13,10 +13,11 @@
           height: 100px;
           background-color: red;
         }
-        :has-slotted {
+        :has-slotted(*) {
           background-color: green;
         }
       </style>
       <slot></slot>
     </template>
+    <div></div>
 </div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-functional-002.tentative.html b/css/css-scoping/has-slotted-functional-002.tentative.html
new file mode 100644
index 00000000000000..a67f788f785633
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-002.tentative.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(...) negative test: no children or white space</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="host"><template shadowrootmode="open">
+    <style>
+    slot {
+        display: block;
+        width: 100px;
+        height: 100px;
+        background-color: green;
+    }
+    :has-slotted(*) {
+        background-color: red;
+    }
+    </style>
+    <slot></slot>
+</template></div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-functional-003.tentative.html b/css/css-scoping/has-slotted-functional-003.tentative.html
new file mode 100644
index 00000000000000..9565b1594c3ed7
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-003.tentative.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(...) negative test: no children, but whitespace present</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="host">
+    <template shadowrootmode="open">
+        <style>
+        slot {
+            display: block;
+            width: 100px;
+            height: 100px;
+            background-color: green;
+        }
+        :has-slotted(*) {
+            background-color: red;
+        }
+        </style>
+        <slot></slot>
+    </template>
+</div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-004.tentative.html b/css/css-scoping/has-slotted-functional-004.tentative.html
similarity index 100%
rename from css/css-scoping/has-slotted-004.tentative.html
rename to css/css-scoping/has-slotted-functional-004.tentative.html
diff --git a/css/css-scoping/has-slotted-005.tentative.html b/css/css-scoping/has-slotted-functional-005.tentative.html
similarity index 100%
rename from css/css-scoping/has-slotted-005.tentative.html
rename to css/css-scoping/has-slotted-functional-005.tentative.html
diff --git a/css/css-scoping/has-slotted-006.tentative.html b/css/css-scoping/has-slotted-functional-006.tentative.html
similarity index 100%
rename from css/css-scoping/has-slotted-006.tentative.html
rename to css/css-scoping/has-slotted-functional-006.tentative.html
diff --git a/css/css-scoping/has-slotted-functional-007.tentative.html b/css/css-scoping/has-slotted-functional-007.tentative.html
new file mode 100644
index 00000000000000..d7e015056300ca
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-007.tentative.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(el + el)</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="host">
+    <template shadowrootmode="open">
+      <style>
+        [name] {
+          display: block;
+          width: 100px;
+          height: 100px;
+          background-color: red;
+        }
+        :has-slotted(div + div) {
+          background-color: green;
+        }
+      </style>
+      <slot></slot>
+      <slot name="after"></slot>
+    </template>
+    <div></div>
+    <div slot="after"></div>
+</div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-functional-changing-001.tentative.html b/css/css-scoping/has-slotted-functional-changing-001.tentative.html
new file mode 100644
index 00000000000000..209a47298e3554
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-changing-001.tentative.html
@@ -0,0 +1,63 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted(...) and :has-slotted through a single shadow root</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+  <div id="test"><template shadowrootmode="open">
+    <slot></slot>
+    <p id="target">This text will be styled.</p>
+    <style>
+      p {
+        color: rgb(0 255 0);
+      }
+      slot:not(:has-slotted) + p {
+        color: rgb(0 0 255);
+      }
+      slot:not(:has-slotted(div)) + p {
+        color: rgb(255 0 255);
+      }
+    </style>
+  </template></div>
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    const fuchsia = 'rgb(255, 0, 255)';
+    test(function () {
+      const test = document.getElementById('test');
+      const target = test.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = ' ';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.replaceChildren();;
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const div = document.createElement('div');
+      test.append(div);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), fuchsia);
+      const node = document.createTextNode(' ');
+      test.replaceChildren(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.innerHTML = '';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-functional-changing-002.tentative.html b/css/css-scoping/has-slotted-functional-changing-002.tentative.html
new file mode 100644
index 00000000000000..36fafcb1dcc49b
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-changing-002.tentative.html
@@ -0,0 +1,65 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted(...) through a single shadow root</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+  <div id="test">
+    <template shadowrootmode="open">
+      <slot></slot>
+      <p id="target">This text will be styled.</p>
+      <style>
+        p {
+          color: rgb(0 255 0);
+        }
+        slot:not(:has-slotted(span)) + p {
+          color: rgb(0 0 255);
+        }
+        slot:not(:has-slotted(div)) + p {
+          color: rgb(255 0 255);
+        }
+      </style>
+    </template>
+  </div>
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    const fuchsia = 'rgb(255, 0, 255)';
+    test(function () {
+      const test = document.getElementById('test');
+      const target = test.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = '<span></span>';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.textContent = '';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const div = document.createElement('div');
+      test.replaceChild(div, test.firstElementChild);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), fuchsia);
+      const span = document.createElement('span');
+      test.replaceChildren(span);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.replaceChildren();
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-functional-changing-003.tentative.html b/css/css-scoping/has-slotted-functional-changing-003.tentative.html
new file mode 100644
index 00000000000000..9914e452088066
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-changing-003.tentative.html
@@ -0,0 +1,64 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted(...) and :has-slotted through multiple shadow roots</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+  <div id="test"><template shadowrootmode="open"><div id="inner"><template shadowrootmode="open">
+    <slot></slot>
+    <p id="target">This text will be styled.</p>
+    <style>
+      p {
+        color: rgb(0 255 0);
+      }
+      slot:not(:has-slotted) + p {
+        color: rgb(0 0 255);
+      }
+      slot:not(:has-slotted(div)) + p {
+        color: rgb(255 0 255);
+      }
+    </style>
+  </template><slot></slot></div></template></div>
+
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    const fuchsia = 'rgb(255, 0, 255)';
+    test(function () {
+      const test = document.getElementById('test');
+      const inner = test.shadowRoot.getElementById('inner');
+      const target = inner.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const node = document.createTextNode(' ');
+      test.replaceChildren(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      node.remove();
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = '<div></div>';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), fuchsia);
+      test.appendChild(node);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.textContent = '';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-functional-changing-004.tentative.html b/css/css-scoping/has-slotted-functional-changing-004.tentative.html
new file mode 100644
index 00000000000000..669162050aab4e
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-changing-004.tentative.html
@@ -0,0 +1,71 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8">
+  <title>Changing content targetting :has-slotted(...) through a single shadow root</title>
+  <link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+</head>
+
+<body>
+
+
+  <div id="test">
+    <template shadowrootmode="open">
+      <div id="inner">
+        <template shadowrootmode="open">
+          <slot></slot>
+          <p id="target">This text will be styled.</p>
+          <style>
+            p {
+              color: rgb(0 255 0);
+            }
+            slot:not(:has-slotted(span)) + p {
+              color: rgb(0 0 255);
+            }
+            slot:not(:has-slotted(div)) + p {
+              color: rgb(255 0 255);
+            }
+          </style>
+        </template>
+      </div>
+    </template>
+  </div>
+
+
+  <script>
+    const blue = 'rgb(0, 0,  255)';
+    const green = 'rgb(0, 255, 0)';
+    const fuchsia = 'rgb(255, 0, 255)';
+    test(function () {
+      const test = document.getElementById('test');
+      const inner = test.shadowRoot.getElementById('inner');
+      const target = inner.shadowRoot.getElementById('target');
+      let styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      const span = document.createElement('span');
+      test.append(span);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      test.removeChild(span);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+      test.innerHTML = '<div></div>';
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), fuchsia);
+      test.replaceChildren(span);
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), blue);
+      span.remove();
+      styles = getComputedStyle(target);
+      assert_equals(styles.getPropertyValue('color'), green);
+    }, name);
+  </script>
+</body>
+
+</html>
diff --git a/css/css-scoping/has-slotted-functional-flattened-001.tentative.html b/css/css-scoping/has-slotted-functional-flattened-001.tentative.html
new file mode 100644
index 00000000000000..f14bdbc776d639
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-flattened-001.tentative.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(*) flattened through multiple slots</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="ancestor">
+    <template shadowrootmode="open">
+        <div id="host">
+            <template shadowrootmode="open">
+              <style>
+                slot {
+                  display: block;
+                  width: 100px;
+                  height: 100px;
+                  background-color: red;
+                }
+                :has-slotted(*) {
+                  background-color: green;
+                }
+              </style>
+              <slot></slot>
+            </template>
+            <slot></slot>
+        </div>
+    </template>
+    <div></div>
+</div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-functional-flattened-002.tentative.html b/css/css-scoping/has-slotted-functional-flattened-002.tentative.html
new file mode 100644
index 00000000000000..ff13ac70963c4f
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-flattened-002.tentative.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(...) negative test: no children or white space</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="ancestor"><template shadowrootmode="open">
+    <div id="host"><template shadowrootmode="open">
+        <style>
+        slot {
+            display: block;
+            width: 100px;
+            height: 100px;
+            background-color: green;
+        }
+        :has-slotted(*) {
+            background-color: red;
+        }
+        </style>
+        <slot></slot>
+    </template><slot></slot></div>
+</template></div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-functional-flattened-003.tentative.html b/css/css-scoping/has-slotted-functional-flattened-003.tentative.html
new file mode 100644
index 00000000000000..bca81b971de20d
--- /dev/null
+++ b/css/css-scoping/has-slotted-functional-flattened-003.tentative.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>:has-slotted(...) flattened through multiple slots, negative test: no children, but whitespace present</title>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<p>Test passes if there is a filled green square.</p>
+<div id="ancestor">
+    <template shadowrootmode="open">
+        <div id="host">
+            <template shadowrootmode="open">
+                <style>
+                slot {
+                    display: block;
+                    width: 100px;
+                    height: 100px;
+                    background-color: green;
+                }
+                :has-slotted(*) {
+                    background-color: red;
+                }
+                </style>
+                <slot></slot>
+            </template>
+        </div>
+        <slot></slot>
+    </template>
+</div>
\ No newline at end of file
diff --git a/css/css-scoping/has-slotted-flattened-004.tentative.html b/css/css-scoping/has-slotted-functional-flattened-004.tentative.html
similarity index 100%
rename from css/css-scoping/has-slotted-flattened-004.tentative.html
rename to css/css-scoping/has-slotted-functional-flattened-004.tentative.html
diff --git a/css/css-scoping/has-slotted-flattened-005.tentative.html b/css/css-scoping/has-slotted-functional-flattened-005.tentative.html
similarity index 100%
rename from css/css-scoping/has-slotted-flattened-005.tentative.html
rename to css/css-scoping/has-slotted-functional-flattened-005.tentative.html
diff --git a/css/css-scoping/has-slotted-flattened-006.tentative.html b/css/css-scoping/has-slotted-functional-flattened-006.tentative.html
similarity index 80%
rename from css/css-scoping/has-slotted-flattened-006.tentative.html
rename to css/css-scoping/has-slotted-functional-flattened-006.tentative.html
index cfe415c7948cbd..fd3dda69bc8a70 100644
--- a/css/css-scoping/has-slotted-flattened-006.tentative.html
+++ b/css/css-scoping/has-slotted-functional-flattened-006.tentative.html
@@ -10,13 +10,13 @@
             <template shadowrootmode="open">
                 <style>
                     [name] {
-                    display: block;
-                    width: 100px;
-                    height: 100px;
-                    background-color: red;
+                        display: block;
+                        width: 100px;
+                        height: 100px;
+                        background-color: red;
                     }
                     :has-slotted(div) + :has-slotted(div) {
-                    background-color: green;
+                        background-color: green;
                     }
                 </style>
                 <slot></slot>
