[CentOS] [OT] Using rsync to backup / restore - when to use (or not use) the -H option switch?

Hello.

After some reading, including the rsync man page, I am still not clear on
this:
When using rsync to backup and restore, when should and when should one
*not*
include hard links (by using the -H option switch)?

A simple example case would be backups for one or just a few light-duty
local workstations. Is there a simple, clear rule about that, or is it  too
complicated for that?