Question: Can multiple 2-way occupancy (AKA motion) sensor switches be used together?

For the top and bottom of a staircase, I want the lights to be on if *either* switch senses motion and the lights stay on until *both* switches time out after not sensing motion.

I know how to wire such a circuit but I want to know if doing so is by-the-code OK (Canada) and how to mark the wires so someone in the future will understand what has been done.

Thanks.

Edit 1: The building is my private home, so I can be confident of (mostly) who will use the stairs and their knowledge of the set-up. However, I could certainly make some tidy P-Touch labels for the faceplates. Writing on the backside of the faceplates and adding a note inside the junction box is possible too. (Are we certain paper in the box isn't a fire hazzard?)

The bulb-changing scenario is something I didn't think of. Perhaps a 3'rd, manual toggle, master circuit kill switch would be possible? Or would that be getting too far away from K.I.S.S. ?

The sensors will face perpendicular to the stairs, detecting people as they enter but only partially while they are on the staircase. I see the concern for the sensors timing out while a person is in mid-climb. However, the staircase is only 12 feet long and receives some natural light during day. A person would need to stop mid-way, out of sight of both sensors and eat a sandwich for enough time to pass to expire the lights. I could mitigate this by adjusting the time-outs, leaving the staircase lit for up to 30 minutes after a sensor last detected motion.

I trust that I am answering questions correctly by "editing" my post. That seems to be what the options suggests I should do.

Answer: 
Have successfully wired 3 Lutron motion sensors to control a common light fixture so that light would be activated regardless of point of entry into room, hall, etc.
Lutron Maestro line of switches can communicate wirelessly to multiple ceiling mounted occupy sensor that use a battery. 

The switches work the lights as normal if the sensors battery dies.

I've installed them and give it a thumbs up.

[Battery Version](http://www.lutron.com/en-US/Products/Pages/Sensors/Occupancy-Vacancy/WirelessRadioPowrSavr/Overview.aspx)