This threatens beef exports: European Union rules bar mixing cattle with beasts that may have foot-and-mouth disease.

ECONOMIST: Zimbabwe��s non-farmers

"There are no rules" for mixing Frank's textile patterns, says Svenskt Tenn in-house interior designer Martin Edvardsson.

WSJ: Nordic Designers Expose Wilder Side in Textiles

Expanding into Saudi Arabia posed a problem because of rules against men and women mixing socially.

WSJ: High Table: Diners Dangle From Crane