Ugly

Uglies are a pejorative term for an unofficial class of ship composed of mismatching components fused together into an aesthetically unpleasant vessel. Uglies can be of any size, and some of them are good enough to pass for "normal" ships. The main thing that ties them all together is how ugly they are.

Emergence
Uglies were practically unheard of before the war, with ship schematics freely available and customers who could afford them. During and after, when the terrestrial government started putting more restrictions on the solarnet and cracking down on software piracy, many people had no choice but to try and build a craft out of whatever parts they could find. The first time the solar system got their first good looks at uglies was when Earth declared a no-fly order, prohibiting any Terran citizens from fleeing to Mars. Software pirates got their hands on a prototype schematic for a personal extraorbital vessel, but there was one problem - the modeller only did the right side of it. But, people were desperate, and so they printed and assembled two right sides, flipped one of them around, and fused the two opposite-facing halves together. And so, images of the mass exodus of refugees fleeing Earth in these half-ships flooded the solarnet, and the general public knew that they were witnessing Earth, the cradle of all civilization, giving its last, desperate gasps. Uglies became the iconic image of the end of an era.

Spread
After the war, when schematics got more and more expensive and harder to come by, free traders started mashing whatever they could find together and flying them out to Wild Space. The corporate-controlled media used this to their advantage to spin it into negative propaganda. The posterchild of Earth's downfall was headed towards Savage Space, where they would be free to congregate in gangs and prey upon the honest working folks in Civilized Space as pirates. And so uglies became the face of the enemy. In Corporate Space, shipwrights and crews of uglies are immediately profiled as outlaws. Some places don't allow uglies into their territory at all. Soon, uglies became a posterchild again: to the average citizen in Corporate Space, they represented the evil that still infests the solar system, that was trying to drag sapient life backwards in the face of progress. But to folks in Wild Space, it's their only means of getting around.