Letter precedent to listing permits applicants to apply to exchanges for listing under defined terms and statutory cross references. Regulation 2 defines operative terms for the Central Listing Authority regime, including applicant, Authority, letter precedent to listing (permission from the Authority to make a listing application to any recognised exchange), listing agreement, listing application (excluding prior in principle requests), listing conditions, and securities. It directs that undefined words derive meanings, in order, from the Act, the Securities Contracts (Regulation) Act, and the Companies Act.