Pottery & Porcelain Marks – Words & Initials – M: From 1945 to 1952, during the Allied occupation after World War II, exports from Japan were marked "Occupied Japan" or "Made in Occupied Japan." Collectors today search for pieces with this time-specific mark. Nelson McCoy Pottery, founded in 1848, made many types of pottery. Do not confuse "McCoy" marks for the Nelson McCoy Co. with those for another company, Brush-McCoy, a common error.