These words are familiar/informal versions of the underlying words.
The connotation of familiarity (my friend Jean-Phi, as opposed to my new colleague Jean-Philippe; cinoche, the place I often go for entertainment, as opposed to cinéma, the neutral word for a movie theater) is what makes them hypocorisms.
Often the ending -i is added to these truncated nameforms. Further diminutives can be added with the suffixes -lein, -(e)l or -chen, e. Often the ending -i is added to these truncated nameforms (Kati, Laci, Julcsi, Ági, Feri).There are however some exceptions, for example Nonni which is an alternative from for Jón.In Japan, diminutive names are made by adding an honorific suffix to a person's name, or to part of the name.The suffix -chan is typically added to a girl's name as a term of endearment. Outside of family, the suffix -kun typically implies a relationship between an authority (the caller) and a subordinate.Thus, it is often used by teachers calling on male students, and a boss or supervisor calling on male employees.Further diminutives can be added with the suffixes -ka, -ke, -kó, -csi, etc., e. Lacika, Ferike, Palkó and Julcsi as a diminutive respectively for László, Ferenc, Pál and Júlia.