R is a velocity measure, defined as a reasonable speed that is consistant with health, mental well being and not being more than five minutes late. It is, therefore, clearly an almost infinitly variable fingure accoridng to circumstances, since the first two factors very not only with speed taken as an absolute, but also with awareness of the third factors. Unless handled with tranquillity this equation can result in considerable stress, ulcers and even death.
(verb) On Blackberry Messenger, when you read someone's message and ignore it. The sender will see an R appear next to their sent message, meaning that they know you read their message and didn't reply.
"She just asked me to hang outtonight but I r'd her."
"Why did you r my message?"
"He just r'd my message!"