Hi, I am guessing that you have taken over an implementation from someone? eVars (like v70 and v71) are custom dimensions... this means they are unique to your suite and organization. Unfortunately, only the person who set those up would know what the definition is.... If that person is no longer available, you might be able to dig into the implementation, figure out where and when those events are triggered and create a definition based on how you see them being used.
Taking over an implementation is hard, and harder still if there isn't proper documentation about it... If you want, I can help with tips on taking over an implementation...