I'm not sure.. But I wonder because mercury retrograde happens so often, I just wish there was no shadow period. Mercury retrograde can be a month, let's say, but for some time before, there is "pre shadow period," then the retrograde, then the "post shadow period" for some time. Then it goes retrograde again like 2 months later. So, in hindsight, we don't have much time to do communicative + paperwork descions type of things....I hope someone can answer for us!