Names the specific vCenter-managed object -- an ESXi host, VM, or other entity -- that this alarm notification concerns, and per the MIB this value must never be empty. Admins use it as the general-purpose replacement for the older host/VM-specific varbinds, identifying the alarm's subject regardless of object type. A trap with vmwVpxdTargetObj set to "datastore1" would identify a datastore, rather than a host or VM, as the object the alarm concerns.