Hey $username!
 

You know how when sending email, you can substitute $username and the registered username of the person will show up in the email.

I think that's fairly clear on how to do that.

But I have seen the same thing done in forums as well, and I'd like to know how to do it. Is this a hack? Or is it straight code?

Thanks in advance.

There is a modification called something along the lines of [you] show the username of the person viewing the post which is available for both 3.0 and 3.5

<a href="https://vborg.vbsupport.ru/showthread.php?t=93145&highlight=hello+%5Busername %5D" target="_blank">https://vborg.vbsupport.ru/showt...%5Busername%5D</a>

Thanks a bunch.