For those of us who have the Tribute module: While I can find gifts that are given to a tribute, and we can generate tribute letters to a specific acknowledgee, there's no way to query on whether those letters were generated, and on what day. This suggestion was added to the KB on 08/04/2005, and last updated on 05/09/2012.
It is really frustrating that I cannot get this information without going directly into the gift tribute tab.
It would be helpful if I could at least get this information from the list of tribute gifts as a separate column, especially the tribute Acknowledge Date and if an acknowledgee box was checked even if the name is not given.