If you choose realname instead of username, and that person has not yet filled out that section, then the reply notifications in the forums is like this..

 {$userName} replied in Winter Riding! forum topic. 

I do understand you can have this set as required for new registers, but i am refering to cases where (as in my case) i converted from another script to Oxwall and those people have just signed in to the new site and are sending feeds before they update their profile. 

Maybe there needs to be a default real name field establish in this case, maybe it could be "hey update your profile" lol :)   or maybe just "no name yet" or something... because getting this  {$userName} is your notification box does not look good.