diff --git a/xml/System.Windows/Application.xml b/xml/System.Windows/Application.xml
index 4bfa99989ca..efdec80b3de 100644
--- a/xml/System.Windows/Application.xml
+++ b/xml/System.Windows/Application.xml
@@ -2476,9 +2476,28 @@ This example illustrates how to use XAML together with application-scope resourc
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets or sets the Fluent theme mode of the application.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>Setting this property controls if Fluent theme is loaded in Light, Dark or System mode.</para>
+          <para>It also controls the application of backdrop and darkmode on window.</para>
+          <para>The four values for the ThemeMode enum are :</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.None" /> - No Fluent theme is loaded.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.System" /> - Fluent theme is loaded based on the system theme.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.Light" /> - Fluent theme is loaded in Light mode.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.Dark" /> - Fluent theme is loaded in Dark mode.</para>
+          <para>These values are predefined in <see cref="P:System.Windows.Application.ThemeMode" /> struct The default value is <see cref="P:System.Windows.ThemeMode.None" />.</para>
+          <para>
+            <see cref="P:System.Windows.Application.ThemeMode" /> and <see cref="P:System.Windows.Application.Resources" /> are designed to be in sync with each other.</para>
+          <para>Syncing is done in order to avoid UI inconsistencies, where the window is in dark mode but the controls within are in light mode or vice versa.</para>
+          <para>Setting this property loads the Fluent theme dictionaries in the application resources.</para>
+          <para>So, if you set this property, it is preferrable to not include Fluent theme dictionaries in the application resources manually. If you do, the Fluent theme dictionaries added in the application resources will take precedence over the ones added by setting this property.</para>
+          <para>This property is experimental and may be removed in future versions.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="TryFindResource">
diff --git a/xml/System.Windows/SystemColors.xml b/xml/System.Windows/SystemColors.xml
index eb776245a19..0a146adedab 100644
--- a/xml/System.Windows/SystemColors.xml
+++ b/xml/System.Windows/SystemColors.xml
@@ -50,7 +50,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the system accent color that's set by the user in OS settings.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -71,9 +71,13 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColor" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>
+            <see cref="P:System.Windows.SystemColors.AccentColor" /> is the system accent color that's set by the user in OS settings.</para>
+          <para>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorBrushKey">
@@ -92,7 +96,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorBrush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -113,7 +117,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the dark shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -134,9 +138,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorDark1" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorDark1BrushKey">
@@ -155,7 +159,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark1Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -176,7 +180,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark1" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -197,7 +201,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the darker shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -218,9 +222,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorDark2" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorDark2BrushKey">
@@ -239,7 +243,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark2Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -260,7 +264,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark2" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -281,7 +285,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the darkest shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -302,9 +306,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorDark3" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorDark3BrushKey">
@@ -323,7 +327,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark3Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -344,7 +348,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorDark3" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -365,7 +369,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColor" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -386,7 +390,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the light shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -407,9 +411,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorLight1" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorLight1BrushKey">
@@ -428,7 +432,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight1Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -449,7 +453,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight1" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -470,7 +474,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the lighter shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -491,9 +495,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorLight2" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorLight2BrushKey">
@@ -512,7 +516,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight2Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -533,7 +537,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight2" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -554,7 +558,7 @@
         <ReturnType>System.Windows.Media.Color</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the lightest shade of the system accent color.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -575,9 +579,9 @@
         <ReturnType>System.Windows.Media.SolidColorBrush</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the brush corresponding to the <see cref="P:System.Windows.SystemColors.AccentColorLight3" /> color.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>When <see cref="P:System.Windows.SystemParameters.HighContrast" /> is <see langword="true" />, this property returns <see cref="P:System.Windows.SystemColors.HighlightTextBrush" />.</remarks>
       </Docs>
     </Member>
     <Member MemberName="AccentColorLight3BrushKey">
@@ -596,7 +600,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight3Brush" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -617,7 +621,7 @@
         <ReturnType>System.Windows.ResourceKey</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the <see cref="P:System.Windows.SystemColors.AccentColorLight3" /> system resource key.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
diff --git a/xml/System.Windows/ThemeMode.xml b/xml/System.Windows/ThemeMode.xml
index afae25cd0cf..45ff43cee8b 100644
--- a/xml/System.Windows/ThemeMode.xml
+++ b/xml/System.Windows/ThemeMode.xml
@@ -28,8 +28,11 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
-    <remarks>To be added.</remarks>
+    <summary>Describes the Fluent theme mode to apply to an application or window.</summary>
+    <remarks>
+      <para>This is an experimental API and may be modified or removed in future releases.</para>
+      <para>Since this is an experimental API, rather than creating a new instance of ThemeMode, use the static properties Light, Dark, System, and None.</para>
+    </remarks>
   </Docs>
   <Members>
     <Member MemberName=".ctor">
@@ -48,8 +51,8 @@
         <Parameter Name="value" Type="System.String" />
       </Parameters>
       <Docs>
-        <param name="value">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="value">The name of the theme mode</param>
+        <summary>Creates a new ThemeMode object with the specified value.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -69,9 +72,11 @@
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the Dark predefined theme mode.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>Whenever this mode is set on <see cref="T:System.Windows.Application" /> or <see cref="T:System.Windows.Window" />, Fluent Dark theme will be applied.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="Equals">
@@ -93,9 +98,10 @@
         <Parameter Name="obj" Type="System.Object" />
       </Parameters>
       <Docs>
-        <param name="obj">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="obj">ThemeMode object to compare with.</param>
+        <summary>Checks whether this instance  is equal to another ThemeMode object.</summary>
+        <returns>
+          <see langword="true" /> if the ThemeMode objects are equal; <see langword="false" /> otherwise.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -121,9 +127,10 @@
         <Parameter Name="other" Type="System.Windows.ThemeMode" />
       </Parameters>
       <Docs>
-        <param name="other">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="other">ThemeMode object to compare with</param>
+        <summary>Checks whether this instance is equal to another ThemeMode object.</summary>
+        <returns>
+          <see langword="true" /> if the ThemeMode objects are equal; <see langword="false" /> otherwise.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -144,8 +151,8 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <summary>Computes the hash code for this object.</summary>
+        <returns>A 32-bit signed integer hash code.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -165,9 +172,11 @@
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the Light predefined theme mode.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>Whenever this mode is set on <see cref="T:System.Windows.Application" /> or <see cref="T:System.Windows.Window" />, Fluent Light theme will be applied.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="None">
@@ -186,9 +195,14 @@
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>
+          <para>Gets the None predefined theme mode.</para>
+        </summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>This is the default value for <see cref="P:System.Windows.Application.ThemeMode" /> and <see cref="P:System.Windows.Window.ThemeMode" /> and it means that Fluent theme will not be applied on the application or window.</para>
+          <para>In case, when <see cref="P:System.Windows.Application.ThemeMode" /> is not set to None, even if <see cref="P:System.Windows.Window.ThemeMode" /> is set to None, the Fluent theme will be applied on the window.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="op_Equality">
@@ -211,10 +225,11 @@
         <Parameter Name="right" Type="System.Windows.ThemeMode" />
       </Parameters>
       <Docs>
-        <param name="left">To be added.</param>
-        <param name="right">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="left">The first ThemeMode object to compare.</param>
+        <param name="right">The second ThemeMode object to compare.</param>
+        <summary>Checks whether two ThemeMode objects are equal.</summary>
+        <returns>
+          <see langword="true" /> if the ThemeMode objects are equal; <see langword="false" /> otherwise.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -238,10 +253,11 @@
         <Parameter Name="right" Type="System.Windows.ThemeMode" />
       </Parameters>
       <Docs>
-        <param name="left">To be added.</param>
-        <param name="right">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="left">The first ThemeMode object to compare.</param>
+        <param name="right">The second ThemeMode object to compare.</param>
+        <summary>Checks whether two ThemeMode objects are not equal.</summary>
+        <returns>
+          <see langword="true" /> if the ThemeMode objects are not equal; <see langword="false" /> otherwise.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -261,9 +277,11 @@
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Get the System predefined theme mode.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>Whenever this mode is set on <see cref="T:System.Windows.Application" /> or <see cref="T:System.Windows.Window" />, Fluent theme will be applied based on the system theme.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="ToString">
@@ -283,8 +301,8 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <summary>Creates a string representation of the ThemeMode object.</summary>
+        <returns>A string representation of this object.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -304,7 +322,7 @@
         <ReturnType>System.String</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets the value of the ThemeMode.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
diff --git a/xml/System.Windows/ThemeModeConverter.xml b/xml/System.Windows/ThemeModeConverter.xml
index 7fe8ec90ab5..e81cc97521e 100644
--- a/xml/System.Windows/ThemeModeConverter.xml
+++ b/xml/System.Windows/ThemeModeConverter.xml
@@ -20,7 +20,7 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Converts instances of other types to and from ThemeMode instances.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -61,10 +61,11 @@
         <Parameter Name="sourceType" Type="System.Type" />
       </Parameters>
       <Docs>
-        <param name="typeDescriptorContext">To be added.</param>
-        <param name="sourceType">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="typeDescriptorContext">The ITypeDescriptorContext for this call.</param>
+        <param name="sourceType">The Type being queried for support.</param>
+        <summary>Determines whether or not this class can convert from a given type.</summary>
+        <returns>
+          <see langword="true" /> if the converter can convert from the provided type; otherwise, <see langword="false" />.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -88,10 +89,11 @@
         <Parameter Name="destinationType" Type="System.Type" />
       </Parameters>
       <Docs>
-        <param name="typeDescriptorContext">To be added.</param>
-        <param name="destinationType">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="typeDescriptorContext">The ITypeDescriptorContext for this call.</param>
+        <param name="destinationType">The Type being queried for support.</param>
+        <summary>Determines whether or not this class can convert to a given type.</summary>
+        <returns>
+          <see langword="true" /> if this converter can convert to the provided type; otherwise, <see langword="false" />.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -116,12 +118,13 @@
         <Parameter Name="source" Type="System.Object" />
       </Parameters>
       <Docs>
-        <param name="typeDescriptorContext">To be added.</param>
-        <param name="cultureInfo">To be added.</param>
-        <param name="source">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="typeDescriptorContext">The ITypeDescriptorContext for this call.</param>
+        <param name="cultureInfo">The CultureInfo which is respected when converting.</param>
+        <param name="source">The object to convert to a <see cref="T:System.Windows.ThemeMode" />.</param>
+        <summary>Attempts to convert to a <see cref="T:System.Windows.ThemeMode" /> from the specified object</summary>
+        <returns>The new <see cref="T:System.Windows.ThemeMode" /> instance.</returns>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">The example object is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="ConvertTo">
@@ -146,13 +149,17 @@
         <Parameter Name="destinationType" Type="System.Type" />
       </Parameters>
       <Docs>
-        <param name="typeDescriptorContext">To be added.</param>
-        <param name="cultureInfo">To be added.</param>
-        <param name="value">To be added.</param>
-        <param name="destinationType">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="typeDescriptorContext">The ITypeDescriptorContext for this call.</param>
+        <param name="cultureInfo">The CultureInfo which is respected when converting.</param>
+        <param name="value">The <see cref="T:System.Windows.ThemeMode" /> to convert.</param>
+        <param name="destinationType">The type to which to convert the ThemeMode instance.</param>
+        <summary>Attempts to convert a <see cref="T:System.Windows.ThemeMode" /> object to the specified type.</summary>
+        <returns>The newly constructed object.</returns>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="value" />  is <see langword="null" />.</exception>
+        <exception cref="T:System.NotSupportedException">
+          <paramref name="value" /> is <see langword="null" /> or not a <see cref="T:System.Windows.ThemeMode" />, or <paramref name="destinationType" /> isn't a valid destination type.</exception>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.Windows/Window.xml b/xml/System.Windows/Window.xml
index b18daecd9d6..63cf03302a2 100644
--- a/xml/System.Windows/Window.xml
+++ b/xml/System.Windows/Window.xml
@@ -2597,9 +2597,28 @@ The following example shows a **File** > **Exit** menu being handled to explicit
         <ReturnType>System.Windows.ThemeMode</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets or sets the Fluent theme mode of the window.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <para>Setting this property controls if Fluent theme is loaded in Light, Dark or System mode.</para>
+          <para>It also controls the application of backdrop and darkmode on window.</para>
+          <para>The four values for the ThemeMode enum are :</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.None" /> - No Fluent theme is loaded. However, if <see cref="P:System.Windows.Application.ThemeMode"/> is not None, then the window will appear as defined in <see cref="P:System.Windows.Application.ThemeMode"/>.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.System" /> - Fluent theme is loaded based on the system theme.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.Light" /> - Fluent theme is loaded in Light mode.</para>
+          <para>
+            <see cref="P:System.Windows.ThemeMode.Dark" /> - Fluent theme is loaded in Dark mode.</para>
+          <para>These values are predefined in <see cref="P:System.Windows.Window.ThemeMode" /> struct The default value is <see cref="P:System.Windows.ThemeMode.None" />.</para>
+          <para>
+            <see cref="P:System.Windows.Window.ThemeMode" /> and <see cref="N:System.Windows.Resources" /> are designed to be in sync with each other.</para>
+          <para>Syncing is done in order to avoid UI inconsistencies, where the window is in dark mode but the controls within are in light mode or vice versa.</para>
+          <para>Setting this property loads the Fluent theme dictionaries in the window resources.</para>
+          <para>So, if you set this property, it is preferrable to not include Fluent theme dictionaries in the window resources manually. If you do, the Fluent theme dictionaries added in the window resources will take precedence over the ones added by setting this property.</para>
+          <para>This property is experimental and may be removed in future versions.</para>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="Title">