When a host has issues/crashes, it will be fenced by oVirt (if some power management options was enabled). But for example when a host is fenced via iDRAC, it just reboots. So the host comes back online, and is added directly to the oVirt cluster again. This isn't always something we want, because what if the host crashed due to some failed hardware (DIMM/CPU/....). It might boot again after a reset via iDRAC, but it might be needed to do some intervention on the host before you want to put it back in the cluster. Therefor it might to good to (have an option to) put a host in maintenance mode after it was fenced. So you can do manual checks/interventions on the host before it gets back in the cluster.
The documentation text flag should only be set after 'doc text' field is provided. Please provide the documentation text and set the flag to '?' again.
The main goal of non-responding host treatment is to make it Up as soon as possible. It's expected that hardware monitoring is performed by some other tool, it's not part of oVirt Engine functionality, so administrators should put host to Maintenance status manually in oVirt Engine after they got an alert about some HW issues from HW monitoring tool. Closing as WONTFIX