From Istaria Lexica
Bureaucrat is the highest ranked userright on the Wiki. The founder of the wiki automatically is the first Bureaucrat. Other users may also be granted this access, by the founder, or by another bureaucrat.
A bureaucrat is able to add and remove user groups using Special:UserRights.
Generally, bureaucrats also have administrator rights, which allows him doing most of the commmunity management tasks.
A list of available users can be found at Special:ListUsers/bureaucrat.