A method is described of controlling at least one operation in at least part of a lifecycle of a replaceable container which is arranged to be removably seated in a dock in a vehicle and which at least before seating in the dock contains an ancillary fluid for use by the vehicle. A controller communicates with a data carrier carried by the container, determines, on the basis of the communication with the data carrier, data associated with at least one of the container, its contents and the vehicle, and controls carrying out of at least one action in relation to at least one of the container and its contents on the basis of the data associated with at least one of the container, its contents and the vehicle.