Fewer than a hundred Sardinian surnames are needed to group together as much as a third of the whole Sardinian population. The most common Sardinian surnames, like "Sanna" (fang), "Piras" (pears), "Pinna" (feather, pen) and "Melis" (honey), derive from the Sardinian language and developed among the Judicates in the Middle Ages as a result of being registered in documents like the condaghes for administrative purposes; most of them derive either from Sardinian place names (e.g. "Fonnesu" "from Fonni", "Busincu" "from Bosa" etc.), from animal names (e.g. "Porcu" "pig", "Piga" "magpie", "Cadeddu" "puppy" etc.) or from a person's occupation, nickname (e.g. "Pittau" "Sebastian"), distinctive trait (e.g. "Mannu" "big"), and filiation (last names ending in -"eddu" which could stand for "son of", e.g. "Corbeddu" "son/daughter of Corbu"); a number of them have undergone Italianization over the most recent centuries (e.g. "Pintori", "Scano", "Zanfarino", "Spano", etc.). Some local surnames also derive from terms of the Paleo-Sardinian substrate. The largest percentage of last names originating from outside the island is from Southern Corsica (like "Cossu", "Cossiga", "Alivesi" and "Achenza", originally from the towns of Olivese and Quenza respectively), followed by Italian (especially Piedmontese but also Campanian, Sicilian and Ligurian, originating from the days of the Savoyard rule and the assimilation policy: some of them have been "Sardinianized", like "Accardu", "Calzinu", "Gambinu", "Raggiu", etc.) and Spanish (especially Catalan) surnames.