Nikon SB-5000 Reference Manual page 52

AF-assist illumination/canceling flash function
(0E-24)
ON: Both AF-assist illumination and flash function activated
OFF: AF-assist illumination canceled, flash function activated
AF ONLY: AF-assist illumination activated, flash function canceled
(only AF-assist illuminator lights up)
ISO sensitivity manual setting
Enables manual setting of ISO sensitivity within the range
B
of 3 to 8000 when ISO sensitivity information has not
been received from the camera (non-CLS compatible SLR
camera is in use)
100: ISO 100
Reset custom settings
YES: Reset to default
NO: Do not reset
B-27