[Captain Kwok]

As it stands now:

Cloaking Device I-V > Availible to all races and can be defeated by Gravitic Sensors I-V.

Cloaking Device VI-X > Availible to all races and can be defeated by Neutron Radiation Scanners I-V.

However, the Romulans and Klingons will have their own cloaks for level VI-X. Romulans have a passive cloak and Klingons have an active cloak. Require either Active or Passive tachyon sensors to be defeated. Capturing either device can result in more efficient (ie reduced size) scanners.