Four official sanctions lists now searchable

The sanctions index now covers four official lists, each downloaded from the
authority that publishes it rather than from any intermediary.

Together they hold tens of thousands of designations: individuals, entities,
vessels and aircraft, with the identifiers, programmes and listing dates as the
publishers record them. The UK list alone arrives as a fifty-megabyte file, so
the import was built to resume where it left off rather than assume it can finish
in one pass.

The lists are re-checked on a schedule and never re-downloaded while the local
copy is still current, which keeps the load on the publishers to what is actually
needed.