IBM IntelliStation Z Pro Type 6866 User Manual page 161

Note: Be sure to route the cables above the top edge or below the
bottom edge of the cable-management arm to avoid
overstressing the cables.
9. Secure the computer in the rack enclosure.
a. Slide the computer into the rack enclosure.
b. Secure the computer to both sides of the rack enclosure by
inserting a long screw through the chassis bracket, mounting rail,
and cage nut.
Appendix B. Rack mounting your computer
145