愛称はフィオちゃん

命名は形式番号の「ANDROID TYPE 01【F】」から　01F→FIO
型番の【F】はキツネ型を表してるよ

Her nickname is Fio

Her name is like that because her formal number is "Android Type 01 [F]" and so 01F→FIO

The [F] in her formal name stands for Fox