The cross of
was the sign used for the Scottish flag before Scotland's union with
England. The Union Jack,
today's British flag, is a
combination of the English St. George's cross (white), the
Scottish cross of St. Andrew (white on blue), and the Irish
cross of St. Patrick (red). The cross of St. Andrew in the
second and common form of it, (surrounded by
five-pointed stars), was also the symbol for the Southern
the American Civil war, the Confederate battle flag.
As a modern ideogram printed on bottles, packages, etc. means harmful or corroding chemical.