J Nagarathna: if the practice associated with a particular deity invokes certain agamas, certain way of worship and one of which may be that persons who are qualified to do that worshop only can do that workship. Therefore, a believer beliefs that only certain persons with qualification can do that worship and the benefit of that worship, the believer also gets. In some shiva temples, you can put water on the lingams but in other temples, you can't because that is part of what they call it as anushthanas or the practice. It is nothing to do with untouchability as such.