CREATE TABLE table_204_568 (id DECIMAL, "pennant" TEXT, "name" TEXT, "hull builder" TEXT, "ordered" TEXT, "laid down" TEXT, "launched" TEXT, "accepted into service" TEXT, "commissioned" TEXT, "est. building cost" TEXT, "fate" TEXT)

what is the last listed pennant ?
SELECT "pennant" FROM table_204_568 ORDER BY id DESC LIMIT 1
SELECT "pennant" FROM "table_204_568" ORDER BY "id" DESC NULLS LAST LIMIT 1