My username on my forum is two letters. People have not been able to use me as a referral or tag me because I'm guessing it takes 3 characters to bring up names? Is it possible to change that?

It’s hardcoded in 3 characters. You would need to edit a couple of files to achieve this. Not recommended. 

Okay, so it seems it's coming up to tag, but now when choosing who referred them (on sign up)

I wonder if would be possible to add a blank space to your user name, like an invisible character. For example, if your user name is ZB, maybe you could try ZB_ (with the underscore being just a tap of the space bar). Haven't tried this -- just an idea ...

That wouldn't help, unfortunately, because if it's invisible, the user wouldn't know to add it after the visible letters.

1 minute ago, Meddysong said:

That wouldn't help, unfortunately, because if it's invisible, the user wouldn't know to add it after the visible letters.

Yes, I was just thinking maybe it would change the two character name to a three character name in the system and cause it to populate in the list when a user starts to type the first two characters.

Oh, you could be right! I thought it needed you to type the third letter before doing the look-up but it seems that you don't, so your idea might actually work 🙂