What does the r after a school name mean?

In the 1970s, kmart used blue light specials to encourage customers to flock to a particular department having a temporary sale. a spinning blue light activated for approximately 30 seconds, and then an in-store announcement informed shoppers of the special savings in the specific department. over time, loyal kmart shoppers learned to flock to the department with the spinning blue light before any announcement of special savings occurred. if kmart was employing classical conditioning techniques, what role did the spinning blue light play?