IBM 1U Installation And Maintenance Manual page 10

Statement 8:
CAUTION:
Never remove the cover on a power supply or any part that has the following
label attached.
Hazardous voltage, current, and energy levels are present inside any
component that has this label attached. There are no serviceable parts inside
these components. If you suspect a problem with one of these parts, contact
a service technician.
Statement 26:
CAUTION:
Do not place any object on top of rack-mounted devices.
viii
1U 17-inch Flat Panel Console Kit: Installation and Maintenance Guide