Dematerialisation requirement: unlisted public companies must issue securities only in dematerialised form and demat promoters' holdings before offers. Unlisted public companies must issue securities only in dematerialised form, facilitate dematerialisation of existing securities, secure an ISIN for each security type, and ensure promoters', directors' and key managerial personnel holdings are dematerialised before any offer, buyback, bonus or rights issue. Companies must pay fees and maintain a multi year security deposit with depositories and registrars, comply with SEBI and depository regulations, and submit specified audit reports half yearly to the Registrar; defaults bar further offers until cleared.