WORDS TWICE-
a.
As a request: “Communication is difficult. Please say every phrase twice.”

b..
As information: “Since communications are difficult, every phrase in this message will be spoken twice.”

WORLD AERONAUTICAL CHARTS-
(See AERONAUTICAL CHART.)
WS-
(See SIGMET.)
(See WEATHER ADVISORY.)
WST-
(See CONVECTIVE SIGMET.)
(See WEATHER ADVISORY.)