Punic-class supercarrier
From Halopedia, the Halo wiki
The UNSC Supercarrier[1] is a heavy warship sub classification (of carrier) within the United Nations Space Command Navy. There were only a few constructed, the only one mentioned is the UNSC Trafalgar, which was destroyed during the First Battle of Reach.
Speculation
Although almost nothing is known about the UNSC Supercarrier, it is reasonable to think that this warship classification would have been one of the most powerful group of ships made by the UNSC known to date. Its designation as a Supercarrier most definitely makes it more powerful than the standard UNSC Carrier, in addition of having 10 meters of Titanium-A armor plating makes it much more resilient than a Carrier. No further mentions have been made about the remaining carriers or about construction of new ones.
