HP DL760 - ProLiant - 1 GB RAM User Manual page 168

HP has designed a self-latching slot-keeper feature to accommodate
full-length expansion boards.
Be sure that the V-shaped slot-keeper tabs on the plastic expansion board guide
are positioned over the forward end of the expansion board. Using the
slot-keepers is especially important when expansion boards are added or when
the server is moved.
Figure 5-25: Full-length self-latching slot-keeper feature
8. Properly connect the expansion board I/O cable.
HP ProLiant DL760 Generation 2 Server User Guide
Installing Hardware Options, Hot-Pluggable
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