Companies Act, 1956
Sec 99 - Reserve
liability of limited company
A limited company may, by special resolution, determine
that any portion of its share capital which has not been already called up
shall not be capable of being called up, except in the event and for the
purposes of the company being wound up, and thereupon that portion of its share
capital shall not be capable of being called up except in that event and for
those purposes.