There are four ‘grades’ in the Warden and Freemen. In order of seniority these are The Capital Burgesses, Assistant Burgesses, Landholder and Commoner. The rules of becoming a commoner are described in the section headed Rules of Commoning and Discommoning.
When a vacancy occurs at Landholder level it is offered to the most senior commoner, if they wish to progress. There are 31 landholders.
When a vacancy occurs at Assistant Burgess level landholders are invited to apply and they are elected by the existing Assistant and Capital Burgesses. There are 24 Assistant Burgesses who are sometimes referred to as the four and twenties.
Similarly Assistant Burgesses are invited to apply for a Capital Burgess vacancy and are elected by the existing Capital Burgesses. There are 13 Capital Burgesses.