NEC N8100-1223F User Manual page 392

9-30 Upgrading Your Server
4.
Press the retention tab at the tip of the additional slot cover to unlock and open the tab.
IMPORTANT:
Doing so could damage the tab.
5.
Remove the blank plate.
IMPORTANT:
6.
Align the board with the grooves of the guide rail, and insert the board slowly and gently.
Do not open the retention tab to 90 degrees or more.
1
2
Keep the blank plate being removed for future use.