Aristocratic Parliamentarianism is a system of governance in which the landed nobility of a nation rule the government through an elected Parliament or similar legislative body. In this system the only group allowed to vote are members of the aristocracy who either hold a noble title or own a significant portion of land. Unlike a pure aristocratic system in which all members of the nobility are entitled to hold seats in the legislature, in aristocratic parliamentarianism the nobility elects the members of the legislature from amongst themselves.
The Unites States prior to the abolition of property requirements for voting is the basis for this model. Many states in the early United States used a form of aristocratic parliamentarianism by requiring that anyone wishing to vote, and by extension hold office, must hold property. While not a nobility in the European sense (Americans after all didn't have noble titles like baron or count), aristocratic parliamentarianism in the US was characterized as rule by landed elites.
In the Kirkland model (named after the nation of its origin, the Kingdom of Kirkland) only those who have been awarded noble titles by the King, or inherited them from ancestors who received their title from the King, are allowed to vote or hold public office. Under this system having property is not required but usually accompanies holding a noble title. Age restrictions do not exist under the Kirkland model as the only condition of consequence is the holding of a noble title.
The legislature of the Kirkland model is required to be unicameral so as to not show preference to any particular section of the nobles. Under the Kirkland model the thought is that if "Upper" and "Lower" houses existed it would be too easy for members of the upper nobility (Grand Dukes, Dukes, and Earls) to gain control of the upper house and therefore ensure a more favorable position for themselves while leaving the lower nobility with little to nothing.
The Drown-Landes (or D-L) model posits that it is possible to create a bicameral legislature in the restrictions on voting made by the Kirkland model. The D-L model holds that as long as any member of the aristocracy can run for either house that it is possible that enough members of the lower nobility will get into the upper house to keep the upper nobility from claiming too much for themselves in the upper house of the legislature. Under the D-L model there also exists the possibility for a quota system in which only a certain number of members of the upper nobility may be seated in the upper house (the ideal number being just below a majority). Another balance proposed by the D-L model is to divide the powers between the houses in such a way that both the upper and lower houses must agree to proposals that would give rewards to certain sections of the nobility.
One criticism of the D-L model is that for the system to remain stable the nobility of the nation must be very advanced and contain a much larger number of lower nobility than upper nobility. Since most beginning micronations have a large upper nobility the D-L model has been suggested only for very well developed nations or nations with no official noble hierarchy.