Rule Definition
Every field of a serializable class must be either serializable or transient. Declaring non-transient fields of non-serializable type inside of a serializable class will result in an exception thrown during the serialization.

Remediation
Make the field type serializable or transient.

Violation Code Sample

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

class SomeType { }

namespace MyObjSerial
{
    [Serializable()]    //Set this attribute to all the classes that want to serialize
    public class Employee
    {
        int EmpId;
        string EmpName;
        SomeType Type; //violation


        //Default constructor
        public Employee()
        {
            EmpId = 0;
            EmpName = null;
            Type = null;

        }
    }
}

Fixed Code Sample

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

namespace MyObjSerial
{

    [Serializable()]
    class SomeType { }

    [Serializable()]
    class Employee
    {
        int EmpId;
        string EmpName;
        SomeType Type; //no violation

        //Default constructor
        public Employee()
        {
            EmpId = 0;
            EmpName = null;
            Type = null;

        }
    }
}

CISQ: ASCRMRLB03