Function-control instructions for controlling a function or feature of a device can be created remotely, locally, or both. A device can receive a function-control instruction or a function-control instruction embedded in received content. Additionally, or alternatively, a function-control instruction can be created locally based on user information or calibration information. Function-control instructions can be passed to an instruction execution application that interprets the function-control instruction. The instruction execution application can pass instructions, based on the function-control instruction, to the device for implementation.