Buy-back definitions set scope for control, associate, small shareholder and tender offer rules under SEBI framework. Definitions prescribe the scope of the buy back framework: control includes rights to appoint directors or direct management through shareholding, management rights, security holders or voting agreements; associate covers persons exercising such control or sharing personnel; core terms like company, Board, merchant banker, registrar, statutory auditor and securities follow statutory meanings. Transactional definitions include tender offer for repurchase by letter of offer, small shareholder for holders below a market value threshold, and working day as any working day of the Board.