You will recognize most of this taxonomy as derived from CGI's published H�rnic material; I've added only a few bits in an effort to frame a more complete and coherent system.
Tariffs: Tariffs are taxes on goods and raw materials imported into or exported from a kingdom. Their amount varies based on the merchandise and on the provenance of the merchandise. Some goods, such as grain or other common-place foodstuffs, might be free of any tariff, but luxury foods (e.g. olives, nuts, spices) that are in high demand often receive high tariffs as a way to maximize revenues. High tariffs are also used to discourage trade in certain goods, usually to protect local craftsmen by making the cost of importing competitive goods prohibitive to both merchants and potential customers. And sometimes high tariffs are used to stifle economic rivals. For example, Chybisa and Melderyn are competitors in the lead and zinc trade, with both kingdoms exporting their surplus to the rest of H�rn. Geography puts Chybisa in a position to price Melderyn out of that trade in Kaldor by applying extremely high tariffs on Melderyni metal as it passes through Chybisa. If Chybisa exercises tariffs in your personal version of H�rn, setting them at just the right rate will be part of Verlid's diplomatic balancing act -- too low and he loses potential revenue; too high and he risks a direct response from Chunel. How much is too much? Well, Melderyn's tariffs range from 10% to 500%, with the average tariff still a very high 40%. A more reasonable rate would be between 5% and 20% for most goods, with 40% applied only to select items or producers.
Thelony: Thelony is a tax on goods and raw materials imported into or exported from a kingdom. It differs from a tariff in that it is a flat rate applied to all goods that are subject to the tax. Like tariffs, thelony is a royal tax and separate and distinct from local hawking and bonding taxes. Some goods, such as grain or other common-place foodstuffs, might be free of thelony, just as some carriers (clergy of recognized churches, the Miner's Guild of Chybisa, etc) might be exempt. Setting the rate at which thelony is levied is a balancing act -- low rates encourage trade through the kingdom but at the cost of potential revenue; rates that are too high actually reduce revenues as merchants find more affordable trade routes through other kingdoms. In this document from medieval Terra, the rate of thelony works out to about 1.7%; and in this document it works out to about 2% -- both seem rather low by H�rnic standards. H�rnic hawking taxes range between 6% and 15% and this seems a reasonable range for thelony in a kingdom where thelony is collected only once on import or export. In kingdoms where thelony will be collected more frequently, such as at tollhouses along internal trade routes, rates similar to the kingdom's bonding rates (usually set between 1% and 3% of the cargo's value) are probably more appropriate. Rates of 20% or the average tariff rate of 40% given in the Cherafir article would be very high and probably considered unreasonable. If you have the appropriate module you might set the thelony rate by using the bonding or hawking tax rates of the kingdom's cities and towns as a guide. Otherwise, set it based on the trade policies you create for the kingdom, or use the dice for inspiration. Though it is possible a tariff schedule and a flat-rate thelony could co-exist, I imagine it is generally an either-or proposition.
Hawking Tax: A tax applied on all goods and raw materials brought into a settlement for the purposes of trade, including raw materials which will be processed into finished goods within the settlement. Note that hawking taxes apply only to goods and materials imported into the settlement; they are not levied on goods produced within the settlement, even if they are subsequently sold there. H�rnic hawking taxes range between 6% and 15%, with 10% being the average. Payment of the tax allows a merchant to display his merchandise and offer it for sale in the Hall of the Mangai, to other merchants or craftsmen, or in the public market, providing he does not violate local or guild laws on such transactions. In rural holdings, a form of hawking tax is imposed by Lords of the Manors on merchants and craftsmen who visit the manor to sell their wares or to purchase raw materials or other goods from their demesne or tenants (see H�rnManor). Common-place foodstuffs (grain, vegetables, most fruit, etc) usually are exempt from hawking taxes. Merchants importing goods or materials into a settlement who desire to avoid or delay payment of hawking taxes must place their merchandise under bond with the local government.
Bonding Fee: Technically not a tax, but a fee paid to cover the expenses of placing goods under bond in the local government's warehouse, usually called a bonding house. Laws in most settlements, however, require all imported goods intended for trade to go into bond unless they have already been subject to local hawking taxes. Since this requirement applies even to imported trade goods that are to be exported immediately after their arrival, the bonding fee is essentially a low-rate tax on goods passing through the settlement. (For example, goods which are unloaded from an arriving ship and placed on carts which immediately leave the town will be subject to the bonding fee.) Since bonding fees are relatively low, most traveling merchants, and even some locally based merchants, use the government's bonding house as a relatively secure place to store their goods until their sale can be arranged, with the buyer paying the hawking tax and removing the goods from bond once the transaction is complete.
Tolls: Tolls are collected to offset the cost of maintaining roadways, bridges, and fords. Residents of the area where the toll is collected are usually exempt, as are members of recognized churches and certain guilds (e.g. the miner's guild). In my version of Chybisa, manor lords are responsible for maintaining the roads that pass through their fiefs and are granted the right to collect tolls to cover their expenses. The King's Road (Genin's Trail) is a special case -- while the lords of the fiefs through which it passes still bear the cost and responsiblity for its upkeep, the work is inspected by the Royal Exchequer's Lord Architect. In other kingdoms, royal roads usually are the responsiblity of the Sheriffs.
Guild License Fees (Rural) and Guild Tax (Urban): On manors and other rural settlements, the guilds pay license fees to the fiefholder for the right to operate their franchises. These fees are generally fixed (see H�rnManor) but on average are roughly equal to 20% of a bonded master's annual income (see H�rnPlayer or the 1st ed. Harndex). In all freetowns and some feudal towns, the local government levies a 5% tax on the gross income of all guild franchises in lieu of fixed license fees. Theoretically, license fees and the guild taxes are paid by the Mangai from the revenues of the master guildsmen's tithing; in rural areas, the practice is for guildsmen to pay their fees directly to the fiefholder and deduct them from their tithing to the guild. Note that Millers pay double taxes (10%) and double tithes (20%).
Property Taxes: Property taxes are levied only on property held in fee simple, hence they are generally only applied in freetowns and some feudal towns. Property taxes are the right of the crown, as ultimate owner of all feudal lands, but those rights are usually granted to the local government with a town charter or as part of a tenant-in-chief's domain. Tax rates vary with locality, but for guildsmen (who are also paying an income tax) a rate of around 6% of the assessed value of their places of business and any attached residences is typical. Everyone else (unguilded businesses and residences) pays around 8% of the assessed value of the property and its structures. Payment of property taxes is the responsibility of the landlord, not the tenant.
Licenses and Exemptions: The lord with a right to taxes, tolls, or fees also has the right to grant exemptions to them. Some parties are granted blanket exemptions -- the Miner's Guild of Chybisa, for example, by royal decree is granted exemption from all thelony, taxes, and tolls; they pay bonding fees only when the guild has need to actually place their metal in the bonding house. The residents of a fief are normally exempt from tolls on that fief's roads, bridges, and fords, passing the cost of their upkeep to visitors and passersby. In Chybisa the churchs of Larani and Peoni are exempt from property taxes and, on most fiefs, are also exempt from local tolls.
Licenses are a form of exemption, usually valid for a fixed period of time or for limited purposes. Lords or other tax authorities might issue them as a form of patronage (granting favors to certain merchants), to encourage the growth of a new trade, or to attract new settlers. Here is an example from Terra's history that grants a certain merchant exemption from hawking taxes for one year. And here is an example of an exemption designed to encourage the growth of a town's textile industry. Licenses could be granted as a benefice, but were often sold, essentially exchanging a fixed fee paid in advance for the variable revenues of the tax.