diff --git a/xml/System.Security.Cryptography.Pkcs/SignerInfo.xml b/xml/System.Security.Cryptography.Pkcs/SignerInfo.xml
index ef85c1b3d60..54af3df916c 100644
--- a/xml/System.Security.Cryptography.Pkcs/SignerInfo.xml
+++ b/xml/System.Security.Cryptography.Pkcs/SignerInfo.xml
@@ -59,9 +59,22 @@
         <Parameter Name="asnEncodedData" Type="System.Security.Cryptography.AsnEncodedData" Index="0" FrameworkAlternate="dotnet-plat-ext-3.0" />
       </Parameters>
       <Docs>
-        <param name="asnEncodedData">To be added.</param>
-        <summary>To be added.</summary>
-        <remarks>To be added.</remarks>
+        <param name="asnEncodedData">The ASN.1 encoded attribute to add to the document.</param>
+        <summary>Adds the specified attribute to the current document.</summary>
+        <remarks>  
+          <format type="text/markdown"><![CDATA[  
+
+If the specified attribute already exists in the document, it is merged with the existing one.
+
+The document is re-encoded after the addition.
+
+         ]]></format>
+         </remarks>
+        <exception cref="T:System.Security.Cryptography.CryptographicException">Cannot find the original signer.
+        
+ -or-
+
+ASN1 corrupted data.</exception>
       </Docs>
     </Member>
     <Member MemberName="Certificate">
@@ -593,9 +606,24 @@
         <Parameter Name="asnEncodedData" Type="System.Security.Cryptography.AsnEncodedData" Index="0" FrameworkAlternate="dotnet-plat-ext-3.0" />
       </Parameters>
       <Docs>
-        <param name="asnEncodedData">To be added.</param>
-        <summary>To be added.</summary>
-        <remarks>To be added.</remarks>
+        <param name="asnEncodedData">The ASN.1 encoded attribute to remove from the document.</param>
+        <summary>Removes the specified attribute from the current document.</summary>
+        <remarks>  
+          <format type="text/markdown"><![CDATA[  
+
+The document is re-encoded after the removal.
+
+         ]]></format>
+         </remarks>
+        <exception cref="T:System.Security.Cryptography.CryptographicException">Cannot find the original signer.
+
+ -or-
+
+Attribute not found.
+
+ -or-
+ 
+ASN1 corrupted data.</exception>
       </Docs>
     </Member>
     <Member MemberName="SignatureAlgorithm">
@@ -810,4 +838,4 @@
       </Docs>
     </Member>
   </Members>
-</Type>
\ No newline at end of file
+</Type>