Some Charitable or Religious Trust Dont Require to File Form 10 Even if Fund Utilization is Less Than 85 % .

This posting is because of a question posed by a premium account subscriber , Mr  Arjun Nedungadi who asked Whether temple having registration u/s 10(23C) and having gross receipts over Rs.1 crore needs to efile Form 10 giving notice of accumulation of income spent below 85% .I  answered in short that  he need not file Form 10  because the the temple trust , as per the question , was registred for exemption u/s 10(23C) of the Income Tax Act . So , here is the detailed answer - why is that so ?