Give the ability to rename none, unspecified, unknown

These 3 names in the reports are very ambiguous and don't give you a good representation of what the data is.  Allow the user to rename these so that they better describe what is happening.  

In my case I have a report that shows internal search terms.  Over 50% of the metrics for this report show as none.  None would be more accurately described by the name "browse" or "non-search".