Comment 2 for bug 683640

As per LSB Init compliancy:

If the status action is requested, the init script will return the following exit status codes.

0 program is running or service is OK
1 program is dead and /var/run pid file exists
2 program is dead and /var/lock lock file exists
3 program is not running
4 program or service status is unknown
5-99 reserved for future LSB use
100-149 reserved for distribution use
150-199 reserved for application use
200-254 reserved

Retrieved from: http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html