SystemInfo.unsupportedIdentifier

public static string unsupportedIdentifier ;

Description

Value returned by SystemInfo string properties which are not supported on the current platform.

using UnityEngine;
using System.Collections;

public class NewBehaviourScript : MonoBehaviour
{
    void Start()
    {
        if (SystemInfo.unsupportedIdentifier != SystemInfo.deviceUniqueIdentifier)
        {
            // use SystemInfo.deviceUniqueIdentifier
        }
    }
}