CREATE TABLE table_23388 ("Team & Boat name" TEXT, "Sail no." TEXT, "Flag" TEXT, "Design Firm" TEXT, "Builder" TEXT, "Skipper" TEXT)

Farr Yacht Design designed boats for how many country/flags?
SELECT COUNT("Flag") FROM table_23388 WHERE "Design Firm" = 'Farr Yacht Design'
SELECT COUNT("Flag") FROM "table_23388" WHERE "Design Firm" = 'Farr Yacht Design'