Bosch B9512G Owner's Manual page 45

Control Panels B93x keypad operation overview | en 45
HELP
The [HELP] key has two uses. First, use the key to open the
keypad's on-display Help. (Press [ESC] to exit Help when
finished.) Also, press and hold the [HELP] key for 2 seconds to
change to the security system's second language.
Bosch Security Systems, Inc. 2015.01 | 02 | F.01U.307.371