Lock-in restriction on specified securities requires non-transferable inscription and depository recording for the prescribed period. Regulation 35 requires that specified securities allotted in a proposed public issue to promoters and others be subject to lock-in and be non-transferable from allotment for the prescribed period; certificates must bear 'non-transferable' and the lock-in period, and dematerialised securities must have the lock-in recorded by the depository. Partly paid securities remain locked-in until three years after they become pari-passu with public-issued securities when their called-up amounts equalise.