Consider the term "OK"

Let us postulate that there ARE time travelers from our future visiting today and in the past. At some time in the future, it is reasonable to assume that the metric system is being used in most cases. Would something that was brand new, never used, and hence (thought to be) perfect be referred to as having zero kilometers.

This could then be referred to as "0 (zero) K", and interpreted by someone in our ( recent) past as "O (letter) K".


So, is this term indicative of time travelers?

And can you think of other phrases that would seem to be remembered phrases of future tourists?