Your effective date is the date that the county is verified (indexed) through.  In Minnesota we have the indexed through date and the verified date.  Our company always uses the verified date as our effective date.  The index date is the date the county has the information indexed through.  Normally this information is not verified.  Completed date would be the date you finished your work.  The search is current through is the same as your effective date.  

 Hope this helps!