Is it common to call others with their initials? If so, could you give me some examples?

Native speaker’s answer
Rebecca
It depends on personal preference, but sometimes people do get called by their initials as a nickname! This is more common when someone has a first and middle/last name that they both use. For example, instead of being called "Alexander James Smith," one might prefer to be called "AJ Smith" as it's shorter. Ex: AJ, how's it going man? Ex: I told TJ to meet us at the soccer field.