Your End Game. When you hand in your resignation, it can kick off a bit of chaos__your position will need to be filled, but your duties will also need to be covered until they can replace you. As part of your resignation letter, it's a good idea to convey what your availability is during that transitional period.
Spot the Signs. Again, you may receive this response if you have specialized knowledge that would make it difficult or time_consuming to hire your replacement__or if it would be helpful for you to be actively involved in that search.