-- The lookup cache gains the IOTA reference QRZ was already sending.
--
-- QRZ's XML carries <iota>EU-048</iota> for an operator on an island, and
-- nothing read it — so the one place an IOTA reference can be known BEFORE the
-- contact is logged was thrown away on every lookup. There is no live "who is
-- on an island right now" feed anywhere (unlike POTA), which makes the callbook
-- record the practical source.
ALTER TABLE callsign_cache ADD COLUMN iota TEXT;