Addition of a diminutive suffix, usually -ie or -y, often to an already shortened name. Although most often applied to the names of children, it is not uncommon for an adult to be referred to by the diminutive, especially by family, friends and close acquaintances: Also, initials of complex names are often used as the hypocorism, e.g.: Brandon William → B W → B Dub Esperanto forms nicknames by suffixing -njo (for females) and -ĉjo (for males) to the first letter(s) of the basic name or word.
Informal French has a number of diminutive nicknames, although not as systematically as in English.
The ending -oche (with or without an intervening consonant or phoneme to make it easier to pronounce) is also sometimes used: cinoche (cinéma), Mac Doche (Mc Donald's), fastoche (easy-peezy, from facile, easy).
Words or names may also be shortened or abbreviated without an O: fixs from fixations, 'ski bindings'; Jean-Phi from Jean-Philippe; amphi from amphithéatre (large classroom or lecture hall); ciné (another informal word for cinéma).
There are however some exceptions, for example Nonni which is an alternative from for Jón.