In order to secure mobile subscriber identity 5G has introduced subscriber identity concealment (SUCI). SUCI is defined in 23.501. The Subscription Concealed Identifier (SUCI) is an identifier designed to protect privacy, which is concealment of SUPI. UDM on the network side is responsible for de-concealment of the SUCI to extract SUPI.
FAT file system was developed for personal computers, FAT comes in difference flavors 12/16/32. Each flavors is from a specific era and the only difference between them is the allocation table.