In the Tar'rani Kingdom, "caste" is a job classification you are born into. It is not quite as strict as what you find in India, and mobility from caste to caste is possible even within your own lifetime. Also, race, caste and class all interact in some fairly unusual ways. For instance, all landowners are Nobles, but not all Nobles actually own land. While all members of the "Shepard Races" are Nobles, select members of the other races can be given Life Honors (honorary nobility) or occasionally even a Life Estate -- they are literally considered to be members of the "Shepard Race" for legal purposes. Even stranger, "Shepard Race" Humaniti may be expelled from their Race for serious crimes. Before I go into the details --

An Aside for Another Useful Concept: "Demesne vs. Fief". While all land is directly "owned" by someone in the nobility, they may "own" it in one of two distinct fashions:

A Fief is a feudal landholding that does not automatically pass to the "owners'" heirs. Inheritance must be confirmed by the liege. Traditionally, this usually happens unless the Fief holder has been a consistently bad landlord and/or has failed to meet their obligations. In effect, the liege has some flexibility to give a fief to someone else, or to redraw borders. The liege also has some power to tell the fief holder how to handle things on the fief. Generally, taxes are based upon a fixed percentage of the Fief's output.

However, a Demesne (almost always) automatically passes to the designated heir, and the "uphill" liege-lord has very little power to tell the Demesne holder how to handle things on that land. The taxes due to the liege are generally fixed in amount (coin, so many cords of wood, so many hides, etc.) from year to year, so that in good years the feudal obligations are not very onerous, but in bad years they may really hurt. Not every landholder has any demesne-lands.

In general, remember that for all castes, feudal obligations run both "down-hill" and "up-hill".

The Important Castes

Scholar Priests: The reference to "priest" does not mean the same as the "charismatic" Rune Priests who come up through the ranks. These folks tend to be (powerful) behind the scenes temple bureaucrats. To be fair, they are often top-notch scholars as well, and in recent times there has been a trend towards scholars who are not identified with any cult. Exclusively nobles.

Great Bards: These folks are quite powerful, as their persons are sacrosanct, and they are not subject to the usual sorts of justice. There job is to observe the important events, remember them, and publicize them. Traditionally they can make or break reputations. In part, they form a pool of traditional oral knowledge about customs of the people. Exclusively nobles.

The Martial Caste consists of:

WrangJaNhim: the warrior-nobility. They are of course exclusively nobles.

Jomeen: Semi-independent peasant landholders, bound by oath to provide a certain number of professional-grade military retainers for long term service. Many of the first generation Jomeenjin were long service Royal Army soldiers retired upon Fief land of the King's feudal underlings, at the King’s direction: while they pay taxes to the local baron, they owe military service (in the person of one or more suitable children) directly to the King. Later, barons decided that they could do the same on their lands and settled long service peasant military retainers to raise the next generation of troops. Usually peasants.

Vaqureen: Cattle herders with enough money to equip themselves. In exchange for certain access rights and a loan or grant to establish themselves, a Vaqureen owes service (as herder and as a reserve cavalry soldier) to his or her liege. Usually peasants.

Navajeen: Coastal boat owners (usually with fishing rights and establishment loans or grants) who become naval reserves or marines, and contribute sons or daughters to the naval and marine units of the Royal Army or armed retainers of the noble houses. Usually peasants.

Artisans: Those who create lasting things of grace and utility.

Armourer-Smiths

Master-Artificers create complex machines.

Mason-Builders

Wood Wrights

Stonemasons

Lesser-Smiths

Tinkers

Entrepreneurs: Those that sell things made by others, or offer their services for money.

Chemi: Alchemists/apothecaries; sometimes are also Medicosi.

Mercadjeen: independent trading houses (usually based out of a city, often in partnership with one or more noble houses)

Medicosi Doctors/surgeons/healers/veterinarians. These are the folks who use both mundane as well as magical healing.

Circadjeen: Itinerant traders, operating in small self-sufficient convoys of wagons. They will have a set route and will trade from place to place along here route. Usually have particular grounds where they will wait out bad weather (mid winter and early spring). They generally need (at least) permission of the local barons to trade, unless they work out of cities, where they will need to pay taxes. Often do their business at various trade fairs.

Peddlers: Very small groups, crewed by a single family, and usually operating on the fringes. Typically have no fixed route and will have just a string of pack-animals.

Landsfolk: that is, farmers.

Tenant Farmers: Owe a fixed amount of service (low) plus a fixed amount of crops/ money. Fairly independent of the liege's control. Usually have to pay various "use" fees in addition for the liege's services (milling, storage, plow rental).

Sharecroppers: Pay a (high) % of their crops, so they share the risk of a bad (or good) year, but the local baron will usually keep a close eye on their activities and meddle more in their day to day affairs. They also owe a fair amount of service, but they usually can expect more help from their liege.

Entertainers

Musicians

"Heavy" Opera Performers

Licensed Courtesans

Players and "Light" Opera Performers

Gieshji

Minstrels

Common Prostitutes

Street Mimes

Laborers

Tinkers: traveling craftsfolk, who own at least their own working tools.

Hoeboys: at least have their own simple agricultural tools.

Jobber-mobbers: who don't even have their own tools.

The Unclean Ones: They deal with the dirty jobs that seem unsavory or spiritually defiling. Human waste, dead bodies (to a certain extent), etc. These folks are not treated too poorly (these jobs are necessary), but are definitely on the bottom of the heap.