By pure PM, I mean one that is free from association with some sports figure or other celebrity. The RM 010 came out at a time when most RMs were pure. Today, I think every RM is impure. There are just different degrees of impurity. The least pure RMs are the ones that have the celebrity's name on the front of the watch. Tolerable levels of impurity are ones like the RM 67-02 that fortunately only mention the name of the back. Why does it matter? Suppose you actually have a watch you keep long term. Imagine you have it 20 years later. Nobody is going to even know or care about the celebrity whose name is polluting the watch.