Nitarri, last name unknown, is a self proclaimed "Mega Mechanical Maniac" who publishes reviews on a multitude of different types of vehicles. Her reviews will sometimes be posted on such pages in the wiki, explaining things in her own unique flavor/take on things. Her true identity is unknown, but it's highly likely she works within the UNT due to her having a lot of reviews on vehicles found there and doesn't have as much information on certain vehicles of enemy factions that they don't have good intel on. Also, she more than likely knows a ton of classified information on many more vehicles that she refrains from making public due to security concerns. This sense of her knowing more than what she lets on likely points to her being some high ranking team member in the developmental/technology/engineering sectors of the UNT, or at least having a high level of clearance for such things. Government officials have no comment on the rumors.
Her guide uses a 5 star ranking, 5 being the best and 0 absolute failure. However, with her bias she ranks older vehicles much higher then they would be if having to go up against newer ones. Therefore, she rates them how they were at the time in their heyday, not how they are now.