Means he'll have to wait for them to have a free house for him. Probably all the housings are full. And depending n his family status if he's single or engage/married or have a kid, they will try to push him to priority list. Means, they'll contact him as soon as a specific housing for him/them is free and he wants to take that house or if he wants to wait for another one. It's a bit of a pain. Because not only that you don't get to see the house unless you sign a list but also the waiting list is also long. Took us almost a month to have ours. We had to stay a friend's house. What unit is he?