This is from the New York Times obituary for Rosa Parks:
On Montgomery buses, the first four rows were reserved for whites. The rear was for blacks, who made up more than 75 percent of the bus system’s riders. Blacks could sit in the middle rows until those seats were needed by whites. Then the blacks had to move to seats in the rear, stand or, if there was no room, leave the bus
This is from the website of Shanghai Racquet Club and Apartments:
1. AYI’s must present a valid Bus Pass on entering the bus on each journey, no pass = no ride…
2. AYI’s will be requested to take up the rear seats of the bus.
3. AYI’s will travel “sub load” and are required follow the instructions of the bus driver if asked to vacate the bus to accommodate members.
Note: ‘Ayi’ means aunt, but is often used in the Mainland to refer to domestic workers and baby sitters.
UPDATE: After the above was published, and noted on Shanghaiist, the Shanghai Racquet Club and Apartments changed the text on their website to the following:
AYI’s must present a valid Bus Pass on entering the bus on each journey.