MLB Guidelines for Opening/Closing Stadium Roofs

We had some discussion a couple of months ago regarding the ability of the Astros to open and close the roof of Minute Maid Park during a game.  As I recall, we weren't altogether clear on what the rules for opening and closing will be.  The Biz of Baseball blog recently published the MLB guidelines for opening and closing roofs of stadiums.  Each team has to provide MLB with written criteria for deciding whether the ballpark roof will be open or closed when the game starts.  If the game starts with a open roof, it cannot be closed during the game unless inclement weather requires the roof to be closed.  If the game starts with a closed roof, the roof may be opened before the 6th inning in order to enhance spectator enjoyment.  Provisions are made for visiting teams to object, and for the umpire to rule on any objections.  The MLB commissioner controls roofs during world series (boy, do we know about that!).  You can see further details on open/close situations in the Biz of Baseball article.