Detect the current switch in a rack or stack
Think of a rack full of cisco switches, you have remote access to the switch, but if you stand in formt of the rack you did not know for sure, which switch you have to check/switch_off/replace.
Sometimes it is helfull to detect the current switch in a rack or stack.
blink with some LEDs
diagnostic start switch 1 test non-disruptive
connect a unused port
compare serial or MAC
trust your documentation