# System.Formats.Asn1

``` diff
 namespace System.Formats.Asn1 {
     public class AsnContentException : Exception {
-        protected AsnContentException(SerializationInfo info, StreamingContext context);
+        [EditorBrowsableAttribute(EditorBrowsableState.Never)]
+        [ObsoleteAttribute("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId="SYSLIB0051", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
+        protected AsnContentException(SerializationInfo info, StreamingContext context);
     }
     public class AsnReader {
+        public AsnReader Clone();
     }
 }
```

