Re: My boss was demonstrating the instrusion sensors on our building
If it's like my company...
Someone, at one time, knew the reset code, or who to call. Fast forward five years, and all those who know are gone, having carefully handed over everything to the new person, who was transferred, so their replacement will have the binder of all knowledge...which seems to be missing the alarm code page (or there is one, but it's the old code, which was changed when the first person left, but the new person, instead of updating the page, simply stuck a yellow Post-It with the new code on...
...which fell off.