Add missing property descriptions for System.Type (#3481)

Author: MSDN-WhiteKnight

xml/System/Type.xml

@@ -10850,9 +10850,17 @@ GetType(Array).IsAssignableFrom(type)
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets a value that indicates whether the type is a byref-like structure.</summary>
+        <value>
+          <see langword="true" /> if the <see cref="T:System.Type" /> is a a byref-like structure; otherwise, <see langword="false" />.</value>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks
+Byref-like structures are declared using `ref struct` keyword in C#. An instance of the byref-like structure can't be placed on the managed heap. For more information, see [Ref struct types](~/docs/csharp/language-reference/keywords/ref.md#ref-struct-types).
+
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="IsClass">
@@ -11428,8 +11436,9 @@ GetType(Array).IsAssignableFrom(type)
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
+        <summary>Gets a value that indicates whether the current <see cref="T:System.Type" /> represents a type parameter in the definition of a generic method.</summary>
+        <value>
+          <see langword="true" /> if the <see cref="T:System.Type" /> object represents a type parameter of a generic method definition; otherwise, <see langword="false" />.</value>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -11670,8 +11679,9 @@ GetType(Array).IsAssignableFrom(type)
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
+        <summary>Gets a value that indicates whether the current <see cref="T:System.Type" /> represents a type parameter in the definition of a generic type.</summary>
+        <value>
+          <see langword="true" /> if the <see cref="T:System.Type" /> object represents a type parameter of a generic type definition; otherwise, <see langword="false" />.</value>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -13125,9 +13135,18 @@ Types that are defined in the .NET Standard are not marked with <xref:System.Ser
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets a value that indicates whether the type is a signature type.</summary>
+        <value>
+          <see langword="true" /> if the <see cref="T:System.Type" /> is a signature type; otherwise, <see langword="false" />.</value>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+ 
+A signature type is a restricted type that can be passed to the <xref:System.Type.GetMethod%2A> method but does not support most of the other reflection functionality. For example, you can obtain the signature type instance corresponding to the generic method parameter by calling the <xref:System.Type.MakeGenericMethodParameter%2A> method.
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="IsSpecialName">
@@ -13289,8 +13308,9 @@ Types that are defined in the .NET Standard are not marked with <xref:System.Ser
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
+        <summary>Gets a value that indicates whether the type is an array type that can represent only a single-dimensional array with a zero lower bound.</summary>
+        <value>
+          <see langword="true" /> if the current <see cref="T:System.Type" /> is an array type that can represent only a single-dimensional array with a zero lower bound; otherwise, <see langword="false" />.</value>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -13318,9 +13338,17 @@ Types that are defined in the .NET Standard are not marked with <xref:System.Ser
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets a value that indicates whether the type is a type definition.</summary>
+        <value>
+          <see langword="true" /> if the current <see cref="T:System.Type" /> is a type definition; otherwise, <see langword="false" />.</value>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+ A <xref:System.Type> instance is a type definition if it represents the type directly defined in assembly, in contrast to types that are constructed on demand based on other types. For example, a primitive type, class, structure, or generic type definition is a type definition, but an array, reference, pointer, or instantiated generic type isn't.
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="IsUnicodeClass">
@@ -13517,9 +13545,17 @@ Types that are defined in the .NET Standard are not marked with <xref:System.Ser
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets a value that indicates whether the type is an array type that can represent a multi-dimensional array or an array with an arbitrary lower bound.</summary>
+        <value>
+          <see langword="true" /> if the current <see cref="T:System.Type" /> is an array type that can represent a multi-dimensional array or an array with an arbitrary lower bound; otherwise, <see langword="false" />.</value>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+If the value of this property is `true` for an array type, it can be used to create single-dimensional or multi-dimensional array instances with arbitrary lower bounds. Otherwise, the array type can only be used to create instances of single-dimensional arrays with a zero lower bound.
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="IsVisible">