Hello Tori B, thanks for your reply.  I opened the register for PNC Checking, and that column displays a checkmark, an asterisk, or nothing, for every transaction, in my Fred Flintstone version of QB.  Clicking on the box toggles among the three options.  I found that if it's blank, then that item shows up in Reconcile as a transaction that hasn't yet been cleared.  If it has a checkmark, then that item shows up in Reconcile as cleared, and QB also adjusts the reconciliation difference between debits and credits accordingly.  If it has an asterisk, the same thing appears to happen as with the checkmark.  I note in the PNC Checking register that all the prior cleared (i.e., Reconciled) transactions have a checkmark, but Check #6222 has a blank box.  So, if there's no transaction in the right pane to offset it, then my reconciliation balance will be off by the amount of that check, $176.21, if I "clear" it either in the register or in Reconcile. 

So, it appears that changing the "uncleared" status of an individual transaction from within the register does not remove it from the list of transactions to Reconcile, at least in this version.  However, this gives me an idea.   After working through all the other transactions that are on my bank statement during the Reconcile process, I can force it to reconcile with a $176.21 difference, and QB will enter a GJE to sweep $176.21 into the Reconciliation Discrepancies account, so that PNC Checking will balance with a zero difference between the columns.   As you probably can tell, I make an effort to keep the books clean, but if there's no other way to do this, and it's ok to force the Reconcile, then I can do it.