Why is there a question re retirement (1099r)? I have always filed using 1099R and never having to offer explanation.

What questions?  Where?  In Turbo Tax or did you get a letter from the IRS?  Did you turn 7 0 1/2?  When you turn 70 1/2 it could ask you if you made a QCD charity contribution or if you took the RMD.  Why did you get a 1099R?  Are you taking a pension  or a IRA withdraw?  

If this was a pension payment and you are being asked if the amount received was a RMD just answer Yes and Continue.  All pension payments are a RMD.