This has been implemented in the 5.12 release (August 2019)
I don't know if you're using Quicken for Mac or Windows. In Quicken for Mac, if you realize you accidentally deleted a transaction, you can just Undo (Command-Z) and the transaction will be restored. And Quicken has multiple undo, so you can back up and undeleted multiple actions if you need to go back several steps. I originally asked for a confirmation message when I started testing Quicken 2015 after many years with Quicken 2007 and earlier, but in practice, I've found the unlimited undo functionality is better than having to confirm every deletion.. (You may not agree; I'm just offering my two cents...)
Perhaps what is needed is a "Deletion notice" - a balloon that appears with each deletion, but fades away in a second or two. Something like the notice that appears when an edit causes a transaction to become hidden because of the current filter settings.This way no confirmation action is required but the user is aware of the deletion in case it is accidental and needs to be undone.I have had a few cases where an accidental deletion has occurred and I did not realize this until after a number of additional actions - I was annoyed with having to undo all the intervening work.And recently, I attempted to duplicate a transaction using the context menu, but my mouse pointer slipped and I instead deleted the transaction - the two actions are adjacent in the menu, with no separator. I was thoroughly mystified when I was expecting two identical transactions in my register but now had none (I had not noticed that these two actions were there together). A notice would have saved me a few moments as I puzzled out what had happened.
Thanks Rocket. I just checked in my version of Quicken Mac 2016 and there is no Edit > Preferences. Perhaps they will add it later.
This post surprised me. I always get a confirmation dialog when I delete a transaction in QW2016. The feature exists, it's just not obvious. In fact, I had to experiment with Preferences to determine where it hides. Edit > Preferences > Register > Notify > Before changing reconciled transactions. This has the side effect of requiring confirmation of deletes.