Problem with two item with subtype identic

[Tallywa 35]

Hello I have a problem with this function:

	if (item->GetType() & ITEM_RING    && item->GetSubType())
    {
        if ((GetWear(WEAR_RING1) && GetWear(WEAR_RING1)->IsSameSpecialGroup(item)) || (GetWear(WEAR_RING2) && GetWear(WEAR_RING2)->IsSameSpecialGroup(item)))
        {
            ChatPacket(CHAT_TYPE_INFO, LC_TEXT("You can't put two same items in the same time."));
            return false;
        }
    }
	

 

I wish I could block the use of two items with an identical subtype. How to do?