More about tagging feature design (not all implemented yet):
We have been thinking to implement 3-level tagging -
1-level (mostly implemented in OMS alpha1): Predefined host type tags (OpenNode, OpenVZ VM, KVM VM, Physical host) - one at the time and always required - we are loading basic management forms based on that tag in WUI
2-level (not implemented): Predefined service name tags (multiple per host - not required) - these tags specify and add additional service management forms by service keyword (which the VM template might set for example) - services like Apache, MySQL, OpenVPN, etc
3-level (not implemented): Freeform tags (global user editable list, multiple per host - not required) - for custom grouping and filtering the host lists