Ship's here in Reality Land have names, so it follows that fictional ships, even starships, have them, too. Most ships have a prefix in front of the name to give people an idea of the vessel's mission. Warships get prefixes like HMS (Her Majesty's Ship) and USS (United States Ship) while other vessels may use MV (Motor Vessel) or RRS (Royal Research Ship)*. In Traveller's Third Imperium, prefixes include INS (Imperial Naval Ship), IISS (Imperial Interstellar Scout Ship), and IMS (Imperial Merchant Ship). I want something similar for the Terran Confederation.
Starting with government-owned ships, the Royal Navy uses HMS (His/Her Majesty's Ship) for all commissioned vessels, from battleships down to couriers. Auxiliaries, such as subsidized merchants and liners called into service, gain the HMNA (His/Her Majesty's Naval Auxiliary) while in service to the Navy, supplanting any existing prefix. For system defense boats, the non-jump capable vessels that protect local systems, the Royal Navy uses HMDB (His/Her Majesty's Defense Boat). The Royal Marines don't have ships of their own, being officially a department of the Royal Navy, but the Royal Army does, mostly transports with the prefix HMAS (His/Her Majesty's Army Ship). Hospital ships in both the Navy and the Army get their own designation, MHMS (His/Her Majesty's Medical Ship); the prefix also gets applied to auxiliaries dedicated for medical evacuation duties.
Outside the military, the Commonwealth has minstries that have their own ships. The largest non-military fleet is held by the Exploration Service under the Ministry of Colonization. The Exploration Service uses the general prefix REV (Royal Exploratory Vessel) for almost all of their ships. The exceptions are the dedicated mail carriers, which get the prefix RPS (Roayl Postal Ship). The Exploration Service tends to use multipurpose ships, so a vessel that had been scouting one month can become a courier the next and a transport following that.
The Ministry of Science also has ships, though it also contracts out research work to universities, corporations, and the Exploration Service. Ministry-owned vessels use the prefix RRV (Royal Research Vessel)**; contracted ships keep their own name and, if any, prefix. The Ministry of Justice is another that has a substantial fleet. However, most of the Ministry's ships are unmarked, allowing agents to investigate undercover, using registries that mask their origin. The overt ships in the Ministry of Justice receive the prefix RCV (Royal Constabulary Vessel).
Individual planets within the Commonwealth may or may not use prefixes. Each planet decides for itself whether to use them. Planet Hypothetical could just call a ship /Sample/, with no prefix. If /Sample/ were used for customs inspections, the prefix could be HCC (Hypothetical Customs Cutter). Vessels from Hypothetical that servied with distinction when in service to the Commonwealth could receive a Royal designation bestowed on them, leading to the prefix RHS (Royal Hypothetical Ship) or even RHCC (Royal Hypothetical Customs Cutter). Merchant ships registered to Hypothetical may use the prefix HCS (Hypothetical Commercial Ship) but not HMS (Hypothetical Merchant Ship) because of the Royal Navy's use of the prefix. All merchant vessels registered within the Commonwealth have the option of the prefix CMS (Commonwealth Merchant Ship), but the use isn't mandated.
How useful is this for the potential NaNoWriMo project this November? This is background work that may not even appear. But Colony Base 182 is just part of the work. The Terran Confederation could easily be a campaign setting, whatever the game mechanics used. Details like the above help define the setting, making it more real.
* As in the not actually being named ship, RRS Boaty McBoatface.
** There is no RRV Labby McLabship.