diff --git a/src/extensions/default/CSSPseudoSelectorHints/PseudoSelectors.json b/src/extensions/default/CSSPseudoSelectorHints/PseudoSelectors.json
index ce326c2ccce..e6a4ed7ce40 100644
--- a/src/extensions/default/CSSPseudoSelectorHints/PseudoSelectors.json
+++ b/src/extensions/default/CSSPseudoSelectorHints/PseudoSelectors.json
@@ -1,30 +1,37 @@
 {
-    "selectors" :
+    "selectors":
     {
         "active":              {"desc": "Selects the active link"},
         "checked":             {"desc": "Selects every checked <input> element"},
+        "default":             {"desc": "Selects every UI element that is the default among a group of similar elements"},
+        "dir(direction)":      {"desc": "Selects every element whose text direction is 'direction'", "text": "dir()"},
         "disabled":            {"desc": "Selects every disabled <input> element"},
         "empty":               {"desc": "Selects every element that has no children/text (including text nodes)"},
         "enabled":             {"desc": "Selects every enabled <input> element"},
         "first-child":         {"desc": "Selects every element that is the first child of its parent"},
         "first-of-type":       {"desc": "Selects every element that is the first element identified by 'type' of its parent"},
         "focus":               {"desc": "Selects the input element which has focus"},
+        "focus-within":        {"desc": "Selects every element which or whose descendant has focus"},
+        "fullscreen":          {"desc": "Selects the element being in full-screen mode"},
         "hover":               {"desc": "Selects elements on mouse over"},
         "in-range":            {"desc": "Selects input elements with a value within a specified range"},
+        "indeterminate":       {"desc": "Selects every indeterminate checkbox or radio button"},
         "invalid":             {"desc": "Selects all input elements with an invalid value"},
-        "lang(language)":      {"desc": "Selects every element with a lang attribute equal to 'language'", "text":"lang()"},
+        "lang(language)":      {"desc": "Selects every element with a lang attribute equal to 'language'", "text": "lang()"},
         "last-child":          {"desc": "Selects every element that is the last child of its parent"},
         "last-of-type":        {"desc": "Selects every element that is the last element of its parent"},
         "link":                {"desc": "Selects all unvisited links"},
-        "not(selector)":       {"desc": "Selects every element that is not an element identified by 'selector'", "text":"not()"},
-        "nth-child(n)":        {"desc": "Selects every element that is the second child of its parent", "text":"nth-child()"},
-        "nth-last-child(n)":   {"desc": "Selects every element that is the second child of its parent, counting from the last child", "text":"nth-last-child()"},
-        "nth-last-of-type(n)": {"desc": "Selects every element that is the nth element of its parent, counting from the last child", "text":"nth-last-of-type()"},
-        "nth-of-type(n)":      {"desc": "Selects every element that is the nth element of its parent",  "text":"nth-of-type(n)"},
-        "only-of-type":        {"desc": "Selects every element that is the only element of this type of its parent"},
+        "matches(selectors)":  {"desc": "Selects every element that is matched by one or more selectors in the 'selectors' list", "text": "matches()"},
+        "not(selector)":       {"desc": "Selects every element that is not an element identified by 'selector'", "text": "not()"},
+        "nth-child(n)":        {"desc": "Selects every element that is the second child of its parent", "text": "nth-child()"},
+        "nth-last-child(n)":   {"desc": "Selects every element that is the second child of its parent, counting from the last child", "text": "nth-last-child()"},
+        "nth-last-of-type(n)": {"desc": "Selects every element that is the nth element of its parent, counting from the last child", "text": "nth-last-of-type()"},
+        "nth-of-type(n)":      {"desc": "Selects every element that is the nth element of its parent",  "text": "nth-of-type(n)"},
         "only-child":          {"desc": "Selects every element that is the only child of its parent"},
+        "only-of-type":        {"desc": "Selects every element that is the only element of this type of its parent"},
         "optional":            {"desc": "Selects input elements with no 'required' attribute"},
         "out-of-range":        {"desc": "Selects input elements with a value outside a specified range"},
+        "placeholder-shown":   {"desc": "Selects all <input> and <textarea> elements currently showing placeholder text"},
         "read-only":           {"desc": "Selects input elements with the 'readonly' attribute specified"},
         "read-write":          {"desc": "Selects input elements with the 'readonly' attribute NOT specified"},
         "required":            {"desc": "Selects input elements with the 'required' attribute specified"},
@@ -33,12 +40,13 @@
         "valid":               {"desc": "Selects all input elements with a valid value"},
         "visited":             {"desc": "Selects all visited links"}
     },
-    "elements" :
+    "elements":
     {
         "after":        {"desc": "Insert something after the content of each element identified by this selector"},
         "before":       {"desc": "Insert something before the content of each element identified by this selector"},
         "first-letter": {"desc": "Selects the first letter of every element identified by this selector"},
         "first-line":   {"desc": "Selects the first line of every element identified by this selector"},
+        "placeholder":  {"desc": "Selects the placeholder text of <input> and <textarea> elements"},
         "selection":    {"desc": "Selects the portion of an element identified by this selector that is selected by a user"}
     }
 }