Sui generis
In sociology, the "sui generis" is what has been externalized, then internalized in the overall public and becomes a part of society that simply exists in its construct. It is not something that is not thought to have been created, because it is imbedded in everyone's way of thinking and being. Instances include the idea of love, or going to school, or clothing belonging to a specific gender. These examples are "sui generis" for they simply exist in society and are widely accepted without thoughts of where they come from or how they were created.
Status in Roman legal system
"Status familiae" is the legal status of an individual in the family. The pater familias had the authority in the family (patria potestas), and everyone was subjected to him based on adgnatio (kinship only from father's side). This had an impact in private law. There is a distinction between alieni iuris (persons under patria potestas) and sui iuris (persons autonomous of patria potestas, who could only be the pater familias himself).
Filius familias had ius suffragii and ius honorum, but in the area of private law he was restricted because of patria potestas.