It is tres popular in Australia (and a bit of a cultural meme) to abbreviate first names of people you know pretty well, at least beyond acquaintance level.
So Sharon becomes Shaz/za. Karen = Kaz/za. Darryl or Darren = Daz/za. Warren = Wozza. We’re fond of the zzz’s, but other names also get ‘the treatment’: John = Johnno, anybody with a surname beginning Mc, gets Macca all too frequently, and then there’s the Hendo-es (short for Henderson), the Smith-ies and the Jones-ies. Apart from the most obstinate names, everybody it seems gets a shortening at some point in their social life.
Does your language group/culture do this?