Well, if I go and copy it directly from the newsletter:
" To combat some of the problems that have occurred, we now are introducing a new section called 'Outskirts'. These sections are specifically to be used whenever a character wishes to have their actions hidden from public view using a mechanic formally known as Fog of War. If a player makes a post in any other section or major city, it is considered to be in full public view and can be considered public knowledge to any character who wishes to know your location. They need only acknowledge a news post stating that you were in a public location."
Terribly sorry I didn't get to this faster. Now, essentially, (And other mods/admins feel free to correct/add information here) Fog of War was designed (Originally) to mark locations where things posted there would be publicly known. EX: Posting in London, Hellsing will know about it because it's their practical front yard.
Now, that mechanic is being replaced with Outskirts, which are areas hidden and things within them would only be known to those inside the thread.
Again, terribly sorry about the delay.