What conditions are applied to the use of E4980A-1CM Rack Mount Kit?

Following conditions are applied to rack mounting of the E4980A;
1) A support rail (even though it is available for one-side only) should be used.
2) No excessive physical load (weight) should be applied on the E4980A mounted in a system rack.
3) Strong mechanical shock or vibration should not be applied to the system rack in which the E4980A is mounted.