Berettiger
Berettiger is a term that is not established in major dictionaries and is rarely used in English or other widely spoken languages. When it appears, it is typically as a neologism or in fictional, humorous, or speculative contexts to denote a person who wears a beret or who is associated with beret-wearing as a defining trait.
Etymology and spelling are not standardized. The form appears to be a compound built from the noun
Usage and connotation vary with context. In fashion commentary or cultural discussion, berettiger might be used
In summary, berettiger is a sparsely used, largely informal coinage with no standard definition or wide recognition.