Walking is when people go on and book a room 11 months out from dates earlier then they actually want to travel and then move it forward every few days until they get to the correct dates.
Once you get a room at 11 months, barring
DVC taking it out of service, no one else can get it as long as you keep changing the check out date before others can check in.
Because this is such a hard to get room, some owners will start trying months in advance in hopes of success.