Английские аббревиатуры WC даны в словаре sokr.ru (со ссылкой на словарь Acronym Finder) на 6 страницах. Вот только две из этих страниц:
WC – Welcome
WC – World Cup
WC – Warcraft (computer game)
WC – Warcraft
WC – Web Cam
WC – Wildcat
WC – World Class
WC – Wild Card (sports; card games)
WC – Wind Chill
WC – Who Cares?
WC – Working Copy
WC – Weather Channel
WC – World Champion
WC – Westchester
WC – Will Consider
WC – Worker's Compensation
WC – Word Count
WC – Worst Case (conditions)
WC – Water Closet (restroom)
WC – Waist Circumference
WC – Weatherford College (Weatherford, Texas)
WC – Westminster College
WC – Wing Commander
WC – Westside Connection
WC – Writing Center
WC – Working Capital
WC – Tungsten Carbide
WC – Water-Cooled
WC – Winston Churchill
WC – Water Column (measure of pressure)
WC – Western Conference (hockey)
WC – Winston Cup
WC – Write Combining
WC – Wisconsin Central (railroad)
WC – Without Charge
WC – Way Cool
WC – Worship Center
WC – Washington Capitals (hockey team)
WC – Wabash College (Indiana)
WC – Wild Cherry
А ещё есть немецкие (в словаре Abk?rzungen):
WC – Warszawa (Polnisches Kfz.-Kennzeichen f?r Warschau)
WC – Water Closet (Toilette)
w/c – week / commencing ( Am Wochenanfang)
WC – Without Charge (Ohne Berechnung)
WC – World Coordinate (Weltweites Koordinatensystem)
Наверное, и в других языках, использующих латиницу, таких аббревиатур немало.