electrical work: create "future boxes" - is this to NEC code?
Putting a box in at the end of the future run, terminating the wires in nuts, and putting a cover on it is standard practice for a "future expansion" outlet of any sort -- putting a label on the cover indicating what it's intended for is a nice touch, but by no means needed by Code.  In fact, you cannot "bury" the box behind the drywall -- it must remain accessible for later use/servicing.