Thanks all for the helpful information.Is there any scenario where you would want to configure the dispatcher to invalidate the entire cache for every author page publish?

I guess, I'm more used to the software development model: You add a comment when you submit a change. Its essential for trouble shooting. I understand its not as important for content edits but when you have multiple people working on the same page I think I can be difficult to track down what happe...

Its not that I don't want to use them, its that they don't seem to do what I want. So the custom property would be a long string? A user would probably need save the date in the field with each they note a change. Perhaps. Sounds a bit ugly.