Thank you all for your time and answers. I tried doing one thing. I kept the item category without special stock indicator E. I tried to create a sales order and with mov type 412 E, I tried to reserve the stock against that sales order. It did give me warning message that the special stock indicator is not maintained but it still reserved the stock in sales order stock category.
Is this the right way to do it? because if this does not have any further repercussions, I can still maintain all the items in sales order with just one category without E indicator and as per requirement user can still reserve the stock against the selected sales order.
thanks,
Binita