This works as follows.
use_instance_uuid = yes (default : yes)
When you create static type monitor for guest machine, "vc.uuid" value takes apart of monitor's key.
In this example, yellow colored is "vc.uuid" of the guest machine.
key = "ESC:V:<vc_uuid>"."Memory"."Memory UsageESC:250"
name = VM01.Memory Usage
use_instance_uuid = no
When you create static type monitor for guest machine, "bios.uuid" value takes apart of monitor's key.
In this example, yellow colored is "bios.uuid" of the guest machine.
key = "ESC:V:<bios_uuid>"."Memory"."Memory UsageESC:250"
name = VM01.Memory Usage