(a) In this Chapter -
"the Act of 1891" means the Stamp Act, 1891;
"certificated securities" means securities other than uncertificated securities;
"Commissioners" means the Revenue Commissioners;
"market maker" means a person who - (i) holds himself or herself out at all normal times in compliance with the rules of the Irish Stock Exchange Limited or the London Stock Exchange Limited as willing to buy and sell securities at a price specified by him or her, and (ii) is recognised as doing so by the Irish Stock Exchange Limited or the London Stock Exchange Limited;
"member firm" means a member firm of the Irish Stock Exchange Limited, or of the London Stock Exchange Limited, which is not acting in the ordinary course of business as a market maker in securities of the kind concerned;
"relevant period" means the period between the 1st day of September, 1996, and the 31st day of March, 1997, or any subsequent period of 6 months ending on the 30th day of September or the 31st