These are additional possible hooks for worlds.
Alien dominated
A majority of the population is non-human.
Alien minority
There is a significant, in terms of number and/or influence, alien population present.
Avoided
The world tends not to be visited for any number of reasons; distance or poor location, little or no exploitable resources, unsavory reputation, a definite lack of interest from the larger galactic community and the like.
Canyon World
Canyon worlds feature breathable or otherwise useful atmospheres only at the lowest altitudes of the planet’s surface, most often at the bottom of valleys and canyons, hence the name. At higher altitudes the atmosphere is either too thin or lacks the right chemical composition to be considered useful.
Complex Etiquette
The population of the world routinely uses detailed, and possibly convoluted, protocols when interacting with others.
Depot
The world is a significant storage/logistics/maintenance site, be it military, commercial or governmental.
Jump Point Limitations
The local Jump point imposes one or more limitations on its use. This could mean restrictions on the size of the vessels passing through it, the frequency with which ships may enter or exit or the fact that it is open only at certain intervals and the like.
Mesa World
A mesa world is the opposite of a canyon world, that is, the atmosphere is only habitable or otherwise useful at higher altitudes. At lower altitudes the atmospheric pressure and/or composition is unhealthy if not actually dangerous.
Notable Terrain
The Notable Terrain hook describes a planet with interesting or unusual terrain features. Examples include the tallest mountain in the sector or strings of overlapping impact craters.
Preserve
The planet has been declared off limits to further development by the State. This may be done to safeguard a valuable biosphere from harm or to protect critical resources until they are needed. Some serve as hunting or nature preserves while others denote archaeological sites. Access to a Preserve is usually monitored for signs of trespass, if not interdicted outright. The State always reserves the right to reclassify the world, thus ending its protected status.
Prison/Exile World
The world exists to house convicted criminals or other undesirable elements.
Reserved
This designation indicates a long populated world that is closed to colonization and further development. Typically this designation is only used in the Core and applied to planets whose main function is as a residence to the upper echelons of society.
Robophilic/Robophobic
The world either warmly welcomes (1–6) or harshly rejects (7–12) robots.
Rogue World
Rogue worlds are solitary bodies traversing the lonely interstellar void between star systems, usually as a result of the interaction between stars and star systems that pass too close to each other. It’s exceedingly rare, but not unknown, that such a world has a jump point associated with it.
Storm World
The world experiences turbulent atmospheric conditions across significant portions of its surface.
Twilight World
The planet is oriented such that the same side always faces its primary. As a result, one side is continually lit and has become an inhospitable desert while the opposite face is perpetually dark and unforgivably cold. The only habitable zone is in the twilight band between the two, so called because the primary is always visible at or near the horizon.