The default should be to just never do it. If you do it, be very very sure that you can trust that person.
One of my guys shared it with me for example and it was totally fine. We always were and still are on great terms and talk to each other from time to time. But we also both 'clicked' from the start. Never really a manager/employee relationship feeling. And while I tried to keep him with us I understood and wished him all the best. He's much happier at his new place now.
Guessing whether your manager might appreciate being able to plan transitions? Forget it! The best you should consider (depending on your level) is to give more notice than the required one. That can be a good compromise but I do hear that in some companies you shouldn't even consider that. But if you feel that they won't escort you out the building the second you give notice anyway than this can be a nice touch. It's a hard decision even then though because you are trying to be nice to your immediate colleagues but make no mistake that in the opposite situation they would not give you more than the mandatory notice period. Even if your manager might want to. HR is HR.
One of my guys shared it with me for example and it was totally fine. We always were and still are on great terms and talk to each other from time to time. But we also both 'clicked' from the start. Never really a manager/employee relationship feeling. And while I tried to keep him with us I understood and wished him all the best. He's much happier at his new place now.
Guessing whether your manager might appreciate being able to plan transitions? Forget it! The best you should consider (depending on your level) is to give more notice than the required one. That can be a good compromise but I do hear that in some companies you shouldn't even consider that. But if you feel that they won't escort you out the building the second you give notice anyway than this can be a nice touch. It's a hard decision even then though because you are trying to be nice to your immediate colleagues but make no mistake that in the opposite situation they would not give you more than the mandatory notice period. Even if your manager might want to. HR is HR.