I worked extensively in mainland China in the tobacco industry.Remember it well Slim. Not sure if you ventured to the Far East in your service and civilian career ,but if you did you will remember the No Spitting signs every where there.
Consumption was rife and the signs in Hong Kong were in educated English No Expectorating and 不随地吐痰 in Cantonese. When I first saw No Expectorating on a lamp post I thought it referred to No prostitution.
Do you remember those elegant young Chinese ladies in their beautiful Cheong Sams showing their hairless shapely limbs ,spoiling it all by coughing up their phlegm into their elegant silk hankies?