If we have an appeal that includes multiple packages (like event registration and auction), when you write the ty letter, you can not include a summary field if the gifts came in different dates. So, if I want to write ONE TY letter for someone who registered April 5th and then won an auction item at the event on April 7th, I can use a summary field for the total gift amounts for that event appeal, but not for the different package benefits. I had to do it manually for an event this fall. It was annoying.