IBM 560 - Manual (Page 96)

Event Bit Definition
Bit 2- - Reserved
Bit 3
- Standby
Bit 4 - Suspend
Bit 5 - RediSafe
Bit 6 - Hibernation
Bit 7 - Power off
Note: If bits are duplicated, the highest bit is available.
A-32 ThinkPad 560/560E SMAPI BIOS