A preparer mistakenly filed an 8606 (2018 return) for an IRA rollover contribution claiming the rolled over amount was a non-deductible contribution.  The return had the proper numbers on 4a and 4b so no income & tax numbers need to be amended but I'm afraid the mistake may come back to haunt the tax-payer in later years in case a preparer assumes that the IRA has non-ded contributions (which it doesn't).  I find all sorts of info on filing an amendment if a Form 8606 has not been filed and should have been, but nothing to the contrary.  I need to cancel/eliminate the 8606 on that year.  Will a simple explanation on the 1040-X suffice?