diff --git a/xml/System.IO.Compression/BrotliCompressionOptions.xml b/xml/System.IO.Compression/BrotliCompressionOptions.xml
index eda3aae2103..dbd8661ba66 100644
--- a/xml/System.IO.Compression/BrotliCompressionOptions.xml
+++ b/xml/System.IO.Compression/BrotliCompressionOptions.xml
@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides compression options to be used with <see cref="T:System.IO.Compression.BrotliStream" />.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -51,9 +51,10 @@
         <ReturnType>System.Int32</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets or sets the compression quality for a Brotli compression stream.</summary>
+        <value>The compression quality for a Brotli compression stream. The default value is 4.</value>
+        <remarks>The higher the quality, the slower the compression. The range is from 0 to 11.</remarks>
+        <exception cref="T:System.ArgumentOutOfRangeException">The value is less than 0 or greater than 11.</exception>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Compression/BrotliStream.xml b/xml/System.IO.Compression/BrotliStream.xml
index a7c70f0fa65..8419cd6bfbc 100644
--- a/xml/System.IO.Compression/BrotliStream.xml
+++ b/xml/System.IO.Compression/BrotliStream.xml
@@ -77,6 +77,8 @@
         <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.BrotliStream" /> class by using the specified stream and compression level.</summary>
         <remarks>To be added.</remarks>
         <exception cref="T:System.ArgumentException">.NET 7 and later: <paramref name="compressionLevel" /> is not defined in the <see cref="System.IO.Compression.CompressionLevel" /> enumeration.</exception>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName=".ctor">
@@ -132,11 +134,14 @@
         <Parameter Name="leaveOpen" Type="System.Boolean" Index="2" FrameworkAlternate="net-9.0" />
       </Parameters>
       <Docs>
-        <param name="stream">To be added.</param>
-        <param name="compressionOptions">To be added.</param>
-        <param name="leaveOpen">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="stream">The stream to which compressed data is written.</param>
+        <param name="compressionOptions">The Brotli options for fine tuning the compression stream.</param>
+        <param name="leaveOpen">
+          <see langword="true" /> to leave the stream open after disposing the <see cref="T:System.IO.Compression.BrotliStream" /> object; otherwise, <see langword="false" />.</param>
+        <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.BrotliStream" /> class by using the specified stream and compression options, and optionally leaves the stream open.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> or <paramref name="compressionOptions" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName=".ctor">
@@ -174,6 +179,8 @@
         <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.BrotliStream" /> class by using the specified stream and compression level, and optionally leaves the stream open.</summary>
         <remarks>To be added.</remarks>
         <exception cref="T:System.ArgumentException">.NET 7 and later: <paramref name="compressionLevel" /> is not defined in the <see cref="System.IO.Compression.CompressionLevel" /> enumeration.</exception>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName=".ctor">
diff --git a/xml/System.IO.Compression/DeflateStream.xml b/xml/System.IO.Compression/DeflateStream.xml
index bd7e1ec71aa..d6b2c69fc0b 100644
--- a/xml/System.IO.Compression/DeflateStream.xml
+++ b/xml/System.IO.Compression/DeflateStream.xml
@@ -362,11 +362,14 @@ You use this constructor when you want to specify whether compression efficiency
         <Parameter Name="leaveOpen" Type="System.Boolean" Index="2" FrameworkAlternate="net-9.0" />
       </Parameters>
       <Docs>
-        <param name="stream">To be added.</param>
-        <param name="compressionOptions">To be added.</param>
-        <param name="leaveOpen">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="stream">The stream to which compressed data is written.</param>
+        <param name="compressionOptions">The options for fine tuning the compression stream.</param>
+        <param name="leaveOpen">
+          <see langword="true" /> to leave the stream object open after disposing the <see cref="T:System.IO.Compression.DeflateStream" /> object; otherwise, <see langword="false" /></param>
+        <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.DeflateStream" /> class by using the specified stream, compression options, and optionally leaves the stream open.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> or <paramref name="compressionOptions" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="BaseStream">
diff --git a/xml/System.IO.Compression/GZipStream.xml b/xml/System.IO.Compression/GZipStream.xml
index 65612798e8f..cf953f70817 100644
--- a/xml/System.IO.Compression/GZipStream.xml
+++ b/xml/System.IO.Compression/GZipStream.xml
@@ -387,11 +387,14 @@ By default, the compression level is set to <xref:System.IO.Compression.Compress
         <Parameter Name="leaveOpen" Type="System.Boolean" Index="2" FrameworkAlternate="net-9.0" />
       </Parameters>
       <Docs>
-        <param name="stream">To be added.</param>
-        <param name="compressionOptions">To be added.</param>
-        <param name="leaveOpen">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="stream">The stream to which compressed data is written.</param>
+        <param name="compressionOptions">The options for fine tuning the compression stream.</param>
+        <param name="leaveOpen">
+          <see langword="true" /> to leave the stream object open after disposing the <see cref="T:System.IO.Compression.GZipStream" /> object; otherwise, <see langword="false" />.</param>
+        <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.GZipStream" /> class by using the specified stream, compression options, and optionally leaves the stream open.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> or <paramref name="compressionOptions" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="BaseStream">
diff --git a/xml/System.IO.Compression/ZLibCompressionOptions.xml b/xml/System.IO.Compression/ZLibCompressionOptions.xml
index 0dad67791c9..8f3ada755e6 100644
--- a/xml/System.IO.Compression/ZLibCompressionOptions.xml
+++ b/xml/System.IO.Compression/ZLibCompressionOptions.xml
@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides compression options to be used with <see cref="T:System.IO.Compression.ZLibStream" />, <see cref="T:System.IO.Compression.DeflateStream" />, and <see cref="T:System.IO.Compression.GZipStream" />.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -51,9 +51,13 @@
         <ReturnType>System.Int32</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets or sets the compression level for a compression stream.</summary>
+        <value>The compression level for a compression stream. The default value is -1.</value>
+        <remarks>
+          <para>Can accept any value between -1 and 9 (inclusive). 0 gives no compression, 1 gives best speed, 9 gives best compression,</para>
+          <para>and -1 requests the default compression level, which is equivalent to 6.</para>
+        </remarks>
+        <exception cref="T:System.ArgumentOutOfRangeException">The value is less than -1 or greater than 9.</exception>
       </Docs>
     </Member>
     <Member MemberName="CompressionStrategy">
@@ -72,9 +76,10 @@
         <ReturnType>System.IO.Compression.ZLibCompressionStrategy</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Gets or sets the compression algorithm for a compression stream.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentOutOfRangeException">The value is not a valid <see cref="T:System.IO.Compression.ZLibCompressionStrategy" /> value.</exception>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Compression/ZLibCompressionStrategy.xml b/xml/System.IO.Compression/ZLibCompressionStrategy.xml
index 5bff34de5c3..d4bfd840a43 100644
--- a/xml/System.IO.Compression/ZLibCompressionStrategy.xml
+++ b/xml/System.IO.Compression/ZLibCompressionStrategy.xml
@@ -13,7 +13,7 @@
     <BaseTypeName>System.Enum</BaseTypeName>
   </Base>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Defines the compression algorithms that can be used for <see cref="T:System.IO.Compression.DeflateStream" />, <see cref="T:System.IO.Compression.GZipStream" />, and <see cref="T:System.IO.Compression.ZLibStream" />.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -34,7 +34,7 @@
       </ReturnValue>
       <MemberValue>0</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Used for normal data.</summary>
       </Docs>
     </Member>
     <Member MemberName="Filtered">
@@ -54,7 +54,9 @@
       </ReturnValue>
       <MemberValue>1</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>
+          <para>Used for data produced by a filter (or predictor). The effect of Filtered is to force more Huffman coding and less string matching; it's an intermediate between Default and HuffmanOnly.</para>
+        </summary>
       </Docs>
     </Member>
     <Member MemberName="Fixed">
@@ -74,7 +76,7 @@
       </ReturnValue>
       <MemberValue>4</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.</summary>
       </Docs>
     </Member>
     <Member MemberName="HuffmanOnly">
@@ -94,7 +96,7 @@
       </ReturnValue>
       <MemberValue>2</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Used to force Huffman encoding only (no string match).</summary>
       </Docs>
     </Member>
     <Member MemberName="RunLengthEncoding">
@@ -114,7 +116,7 @@
       </ReturnValue>
       <MemberValue>3</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Used to limit match distances to one (run-length encoding). Gives better compression for PNG image data.</summary>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.IO.Compression/ZLibStream.xml b/xml/System.IO.Compression/ZLibStream.xml
index d198e01e82a..3a8215c0c57 100644
--- a/xml/System.IO.Compression/ZLibStream.xml
+++ b/xml/System.IO.Compression/ZLibStream.xml
@@ -158,11 +158,14 @@
         <Parameter Name="leaveOpen" Type="System.Boolean" Index="2" FrameworkAlternate="net-9.0" />
       </Parameters>
       <Docs>
-        <param name="stream">To be added.</param>
-        <param name="compressionOptions">To be added.</param>
-        <param name="leaveOpen">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="stream">The stream to which compressed data is written.</param>
+        <param name="compressionOptions">The ZLib options for fine tuning the compression stream.</param>
+        <param name="leaveOpen">
+          <see langword="true" /> to leave the stream object open after disposing the <see cref="T:System.IO.Compression.ZLibStream" /> object; otherwise, <see langword="false" />.</param>
+        <summary>Initializes a new instance of the <see cref="T:System.IO.Compression.ZLibStream" /> class by using the specified stream and compression options, and optionally leaves the stream open.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="stream" /> or <paramref name="compressionOptions" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="BaseStream">