Dar el alta/ el baja

[pjt33]

I think that both are commonly used in various contexts. In the medical system in Spain, dar la baja is when a doctor signs someone off work and dar el alta is when they say that you're fit to work, also used to say that you're sufficiently recovered to not need a follow-up appointment when you weren't actually off work. In other contexts dar el alta can be to sign up for a service, and dar la baja is to cancel it. And there seems to be some military usage which I haven't looked into.