diff --git a/xml/System.IO.Enumeration/FileSystemEnumerable`1.xml b/xml/System.IO.Enumeration/FileSystemEnumerable`1.xml
index a0bd9871d5f..36ad1d0b96d 100644
--- a/xml/System.IO.Enumeration/FileSystemEnumerable`1.xml
+++ b/xml/System.IO.Enumeration/FileSystemEnumerable`1.xml
@@ -1,4 +1,4 @@
-<Type Name="FileSystemEnumerable&lt;TResult&gt;" FullName="System.IO.Enumeration.FileSystemEnumerable&lt;TResult&gt;">
+<Type Name="FileSystemEnumerable&lt;TResult&gt;" FullName="System.IO.Enumeration.FileSystemEnumerable&lt;TResult&gt;">
   <TypeSignature Language="C#" Value="public class FileSystemEnumerable&lt;TResult&gt; : System.Collections.Generic.IEnumerable&lt;TResult&gt;" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit FileSystemEnumerable`1&lt;TResult&gt; extends System.Object implements class System.Collections.Generic.IEnumerable`1&lt;!TResult&gt;, class System.Collections.IEnumerable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Enumeration.FileSystemEnumerable`1" />
@@ -188,7 +188,15 @@
       <Docs>
         <summary>Gets an enumerator that can be used to iterate.</summary>
         <returns>An enumerator instance.</returns>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Enumeration.FileSystemEnumerable`1> instance is cast to an <xref:System.Collections.IEnumerable> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Enumeration/FileSystemEnumerator`1.xml b/xml/System.IO.Enumeration/FileSystemEnumerator`1.xml
index e8323f3630e..f889b408bb8 100644
--- a/xml/System.IO.Enumeration/FileSystemEnumerator`1.xml
+++ b/xml/System.IO.Enumeration/FileSystemEnumerator`1.xml
@@ -1,4 +1,4 @@
-<Type Name="FileSystemEnumerator&lt;TResult&gt;" FullName="System.IO.Enumeration.FileSystemEnumerator&lt;TResult&gt;">
+<Type Name="FileSystemEnumerator&lt;TResult&gt;" FullName="System.IO.Enumeration.FileSystemEnumerator&lt;TResult&gt;">
   <TypeSignature Language="C#" Value="public abstract class FileSystemEnumerator&lt;TResult&gt; : System.Runtime.ConstrainedExecution.CriticalFinalizerObject, System.Collections.Generic.IEnumerator&lt;TResult&gt;" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract beforefieldinit FileSystemEnumerator`1&lt;TResult&gt; extends System.Runtime.ConstrainedExecution.CriticalFinalizerObject implements class System.Collections.Generic.IEnumerator`1&lt;!TResult&gt;, class System.Collections.IEnumerator, class System.IDisposable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Enumeration.FileSystemEnumerator`1" />
@@ -383,7 +383,15 @@ As described in the remarks for <xref:System.Collections.IEnumerator>, the `Rese
       <Docs>
         <summary>Gets the currently visited object.</summary>
         <value>The currently visited object.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Enumeration.FileSystemEnumerator`1> instance is cast to an <xref:System.Collections.IEnumerator> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="TransformEntry">
diff --git a/xml/System.IO.Log/LogExtentCollection.xml b/xml/System.IO.Log/LogExtentCollection.xml
index 7720639b906..a1821beca93 100644
--- a/xml/System.IO.Log/LogExtentCollection.xml
+++ b/xml/System.IO.Log/LogExtentCollection.xml
@@ -1,4 +1,4 @@
-<Type Name="LogExtentCollection" FullName="System.IO.Log.LogExtentCollection">
+<Type Name="LogExtentCollection" FullName="System.IO.Log.LogExtentCollection">
   <TypeSignature Language="C#" Value="public sealed class LogExtentCollection : System.Collections.Generic.IEnumerable&lt;System.IO.Log.LogExtent&gt;" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi sealed beforefieldinit LogExtentCollection extends System.Object implements class System.Collections.Generic.IEnumerable`1&lt;class System.IO.Log.LogExtent&gt;, class System.Collections.IEnumerable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Log.LogExtentCollection" />
@@ -413,7 +413,15 @@
       <Docs>
         <summary>Gets an enumerator for the <see cref="T:System.IO.Log.LogExtent" /> instances in this collection. This method cannot be inherited.</summary>
         <returns>An enumerator for the <see cref="T:System.IO.Log.LogExtent" /> instances in this collection.</returns>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Log.LogExtentCollection> instance is cast to an <xref:System.Collections.IEnumerable> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Log/ReservationCollection.xml b/xml/System.IO.Log/ReservationCollection.xml
index 5f05e28e84b..292c519d685 100644
--- a/xml/System.IO.Log/ReservationCollection.xml
+++ b/xml/System.IO.Log/ReservationCollection.xml
@@ -1,4 +1,4 @@
-<Type Name="ReservationCollection" FullName="System.IO.Log.ReservationCollection">
+<Type Name="ReservationCollection" FullName="System.IO.Log.ReservationCollection">
   <TypeSignature Language="C#" Value="public abstract class ReservationCollection : System.Collections.Generic.ICollection&lt;long&gt;, System.Collections.Generic.IEnumerable&lt;long&gt;" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract beforefieldinit ReservationCollection extends System.Object implements class System.Collections.Generic.ICollection`1&lt;int64&gt;, class System.Collections.Generic.IEnumerable`1&lt;int64&gt;, class System.Collections.IEnumerable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Log.ReservationCollection" />
@@ -628,7 +628,15 @@ recordSequence.Append(undoRecordData, userSqn, previousSqn, RecordAppendOptions.
       <Docs>
         <summary>Returns an enumerator that can iterate through the <see cref="T:System.IO.Log.ReservationCollection" />. This method cannot be inherited.</summary>
         <returns>An enumerator that can iterate through the <see cref="T:System.IO.Log.ReservationCollection" />.</returns>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Log.ReservationCollection> instance is cast to an <xref:System.Collections.IEnumerable> interface.
+
+          ]]></format>
+        </remarks>
         <exception cref="T:System.InvalidOperationException">The operation is invalid for one of the following reasons:  
   
 -   The enumeration has ended.  
diff --git a/xml/System.IO.Packaging/Package.xml b/xml/System.IO.Packaging/Package.xml
index d10dc58ba42..93cba830a6d 100644
--- a/xml/System.IO.Packaging/Package.xml
+++ b/xml/System.IO.Packaging/Package.xml
@@ -1,4 +1,4 @@
-<Type Name="Package" FullName="System.IO.Packaging.Package">
+<Type Name="Package" FullName="System.IO.Packaging.Package">
   <TypeSignature Language="C#" Value="public abstract class Package : IDisposable" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract beforefieldinit Package extends System.Object implements class System.IDisposable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Packaging.Package" />
@@ -2059,7 +2059,15 @@
       <Parameters />
       <Docs>
         <summary>This member supports the [!INCLUDE[TLA#tla_winclient](~/includes/tlasharptla-winclient-md.md)] infrastructure and is not intended for application use.  Use the type-safe <see cref="M:System.IO.Packaging.Package.Dispose(System.Boolean)" /> method instead.</summary>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Packaging.Package> instance is cast to an <xref:System.IDisposable> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Packaging/PackageRelationshipCollection.xml b/xml/System.IO.Packaging/PackageRelationshipCollection.xml
index 62a03e5de08..09ee592fb11 100644
--- a/xml/System.IO.Packaging/PackageRelationshipCollection.xml
+++ b/xml/System.IO.Packaging/PackageRelationshipCollection.xml
@@ -1,4 +1,4 @@
-<Type Name="PackageRelationshipCollection" FullName="System.IO.Packaging.PackageRelationshipCollection">
+<Type Name="PackageRelationshipCollection" FullName="System.IO.Packaging.PackageRelationshipCollection">
   <TypeSignature Language="C#" Value="public class PackageRelationshipCollection : System.Collections.Generic.IEnumerable&lt;System.IO.Packaging.PackageRelationship&gt;" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit PackageRelationshipCollection extends System.Object implements class System.Collections.Generic.IEnumerable`1&lt;class System.IO.Packaging.PackageRelationship&gt;, class System.Collections.IEnumerable" />
   <TypeSignature Language="DocId" Value="T:System.IO.Packaging.PackageRelationshipCollection" />
@@ -146,7 +146,15 @@
       <Docs>
         <summary>This type or member supports the Windows Presentation Foundation infrastructure and is not intended to be used directly from your code.</summary>
         <returns>Do not use - use <see cref="M:System.IO.Packaging.PackageRelationshipCollection.GetEnumerator" />.</returns>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.Packaging.PackageRelationshipCollection> instance is cast to an <xref:System.Collections.IEnumerable> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO/BinaryWriter.xml b/xml/System.IO/BinaryWriter.xml
index bac274301e7..dbfa7bcdd8e 100644
--- a/xml/System.IO/BinaryWriter.xml
+++ b/xml/System.IO/BinaryWriter.xml
@@ -1,4 +1,4 @@
-<Type Name="BinaryWriter" FullName="System.IO.BinaryWriter">
+<Type Name="BinaryWriter" FullName="System.IO.BinaryWriter">
   <TypeSignature Language="C#" Value="public class BinaryWriter : IDisposable" FrameworkAlternate="dotnet-uwp-10.0;netcore-1.0;netcore-1.1;netcore-2.0;netcore-2.1;netcore-2.2;netframework-1.1;netframework-2.0;netframework-3.0;netframework-3.5;netframework-4.0;netframework-4.5;netframework-4.5.1;netframework-4.5.2;netframework-4.6;netframework-4.6.1;netframework-4.6.2;netframework-4.7;netframework-4.7.1;netframework-4.7.2;netframework-4.8;netstandard-1.0;netstandard-1.1;netstandard-1.2;netstandard-1.3;netstandard-1.4;netstandard-1.5;netstandard-1.6;netstandard-2.0;xamarinandroid-7.1;xamarinios-10.8;xamarinmac-3.0" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit BinaryWriter extends System.Object implements class System.IDisposable" FrameworkAlternate="dotnet-uwp-10.0;netcore-1.0;netcore-1.1;netcore-2.0;netcore-2.1;netcore-2.2;netstandard-1.0;netstandard-1.1;netstandard-1.2;netstandard-1.3;netstandard-1.4;netstandard-1.5;netstandard-1.6;netstandard-2.0" />
   <TypeSignature Language="DocId" Value="T:System.IO.BinaryWriter" />
@@ -891,10 +891,18 @@
       <Parameters />
       <Docs>
         <summary>Releases the unmanaged resources used by the <see cref="T:System.IO.BinaryWriter" /> and optionally releases the managed resources.</summary>
-        <remarks>To be added.</remarks>
-        <related type="Article" href="/dotnet/standard/io/">File and Stream I/O</related>
-        <related type="Article" href="/dotnet/standard/io/how-to-read-text-from-a-file">How to: Read Text from a File</related>
-        <related type="Article" href="/dotnet/standard/io/how-to-write-text-to-a-file">How to: Write Text to a File</related>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.IO.BinaryWriter> instance is cast to an <xref:System.IDisposable> interface.
+
+          ]]></format>
+        </remarks>
+        <related type="Article" href="~/docs/standard/io/index.md">File and Stream I/O</related>
+        <related type="Article" href="~/docs/standard/io/how-to-read-text-from-a-file.md">How to: Read Text from a File</related>
+        <related type="Article" href="~/docs/standard/io/how-to-write-text-to-a-file.md">How to: Write Text to a File</related>
       </Docs>
     </Member>
     <MemberGroup MemberName="Write">
diff --git a/xml/System.IO/FileSystemAclExtensions.xml b/xml/System.IO/FileSystemAclExtensions.xml
index 210df9990c1..9f4c9a37e9f 100644
--- a/xml/System.IO/FileSystemAclExtensions.xml
+++ b/xml/System.IO/FileSystemAclExtensions.xml
@@ -1,4 +1,4 @@
-<Type Name="FileSystemAclExtensions" FullName="System.IO.FileSystemAclExtensions">
+<Type Name="FileSystemAclExtensions" FullName="System.IO.FileSystemAclExtensions">
   <TypeSignature Language="C#" Value="public static class FileSystemAclExtensions" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract sealed beforefieldinit FileSystemAclExtensions extends System.Object" />
   <TypeSignature Language="DocId" Value="T:System.IO.FileSystemAclExtensions" />
@@ -210,11 +210,21 @@ namespace ConsoleApp
         <Parameter Name="path" Type="System.String" Index="1" FrameworkAlternate="dotnet-plat-ext-5.0;net-5.0" />
       </Parameters>
       <Docs>
-        <param name="directorySecurity">To be added.</param>
-        <param name="path">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <param name="directorySecurity">An object that determines the access control and audit security for the directory.</param>
+        <param name="path">The path of the directory to create.</param>
+        <summary>Creates a directory and returns it, ensuring it is created with the specified directory security. If the directory already exists, the existing directory is returned.</summary>
+        <returns>A directory information object representing either a created directory with the provided security properties, or the existing directory.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This extension method was added to .NET Core to bring the functionality that was provided by the `System.IO.Directory.CreateDirectory(System.String,System.Security.AccessControl.DirectorySecurity)` .NET Framework method.
+
+          ]]></format>
+        </remarks>
+        <exception cref="T:System.ArgumentNullException"><paramref name="directorySecurity" /> or <paramref name="path" /> is <see langword="null" />.</exception>
+        <exception cref="T:System.ArgumentException"><paramref name="path" /> is empty.</exception>
       </Docs>
     </Member>
     <Member MemberName="GetAccessControl">
diff --git a/xml/System.IO/UnmanagedMemoryStream.xml b/xml/System.IO/UnmanagedMemoryStream.xml
index 9a9c5d122f0..437ee8d8c1e 100644
--- a/xml/System.IO/UnmanagedMemoryStream.xml
+++ b/xml/System.IO/UnmanagedMemoryStream.xml
@@ -1,4 +1,4 @@
-<Type Name="UnmanagedMemoryStream" FullName="System.IO.UnmanagedMemoryStream">
+<Type Name="UnmanagedMemoryStream" FullName="System.IO.UnmanagedMemoryStream">
   <TypeSignature Language="C#" Value="public class UnmanagedMemoryStream : System.IO.Stream" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit UnmanagedMemoryStream extends System.IO.Stream" />
   <TypeSignature Language="DocId" Value="T:System.IO.UnmanagedMemoryStream" />
@@ -646,10 +646,10 @@
         <Parameter Name="bufferSize" Type="System.Int32" Index="2" FrameworkAlternate="net-5.0" />
       </Parameters>
       <Docs>
-        <param name="callback">To be added.</param>
-        <param name="state">To be added.</param>
-        <param name="bufferSize">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="callback">The callback tho handle the stream contents to be copied.</param>
+        <param name="state">A user-defined state, passed to the callback.</param>
+        <param name="bufferSize">The buffer size of the span.</param>
+        <summary>Copies the current unmanaged memory stream instance contents and sends them to the specified callback for processing.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>