I tend to group my units roles as such:
- Corvette: At 3,125 Tons these ships tend to fulfill the role of escorts, scouts, survey ships, dedicated fighter killers, gunboats, missile boats and a whole slew of other things. They are defined by their weight with no regard to their role.
- Frigate: The backbone of my navy, they weigh in at 6,250 tons and fulfill most roles. Regardless of their mission profile, armament or anything else, they are always referred to as "Frigates". Even if they are for all intensive purposes a Carrier, the designation is related to their tonnage and therefore a 6,250 Ton Carrier in my Navy is called a Frigate. Frigate is a catchall for my Sub-Capital vessels.
- Heavy Corvette & Heavy Frigate: These special designations are dictated by role and are sometimes referred to as Double Corvettes or Double Frigates. They mass 6,250 tons and 12,500 Tons respectively and possess a rarely used nomenclature.
- Cruiser: A ship designed for independent operation and built to a tonnage not exceeding 12,500 Tons. Typically carries a mixed armament which let's it engage a variety of vessels, as well as a comprehensive sensors suite. Not typically armed with missiles of any sort, it is important to note that I only define a Cruiser as such if it possesses a Jump Drive.
- Light Cruiser: In every way a Cruiser, but lacking a Jump Drive, the Light Cruiser also cannot weigh more the 12,500 Tons and tends to be more specialized. Typically used in the Fire Support or Sensor Support role, and very often armed with missiles. Light Cruisers in my Navy are perhaps best defined as a scaled down Cruiser, and usually retain at least some of their general utility with an eye towards system scale independent actions versus a proper Cruiser's inter-system capabilities.
- Warp Cruiser: A variant of Cruiser that forgoes the general capabilities in favor of a long range Jump Drive with a high Squadron capacity. Typically focuses on higher speed as well, and sacrifices armament. Almost exclusively Beam Armed.
- Destroyer: Similar to the Light Cruiser, but even more specialized. Destroyer's in my Navy are a class of warship designed to excel at destroying much larger foes. Typically lacking in general capabilities even moreso than Light Cruisers, these are typically Beam armed warships with a focus on destroying enemy Capital Ships and Super Capital Ships. They often possess heavier armor and powerful shields as well.
- Carrier: A parasite carrier massing at least 12,500 Tons, but larger versions are permitted without the need to reclassify. "Fleet Carriers" are the un-official nomenclature of Carriers possessing a Jump Drive of their own. Carriers are typically built to accommodate Beam Fighters or Missile Fighters, with the former being described as "Beam Carriers" and the latter as "Strike Carriers"
- Raiding Carrier: A sub group of Carriers which are built around a Cloaking Device and also possess a Jump Drive. They're typically quite slow and more often than not unarmed. They're used specifically for interdiction and boarding operations. They usually mass 12,500 tons, but can vary to as much as 25,000 Tons down to 6,250 Tons depending on the exact mission profile of the ship.
- Super-Capital: Often just scaled up versions of 12,500 Ton "Capital Ships", these ships mass anywhere from as little of 25,000 Tons all the way up to 150,000 ton behemoths and are expressly designed for an offensive war. Battlecruisers are the exception, as they are 25,000 Ton Cruisers focused specifically on being faster, up gunned versions of regular Cruisers and possess the same roles.