Has anyone tried giving a user a nick name?

Nitzan Matzkevich

I work for a Korean company, and many employees have parts of their name in common (for example "woo"). When you try to tag a user in a comment, the list of people with similar name (or name parts) is so long, that you can't find some of the users. Even typing the full name doesn't work.

Anyone has any ideas? Is there a way to give the user a nick name to differentiate it?

Iago Docando

All you can do is "play" with the actual user name and the way the name shows in screen (full name). 

The user account has 3 main IDs: email, user name, and full name

You can search indistinctively by any of those so as far as I understand the "nick" you're looking for would be the user name.