WASSUP!
$user_profile[16], $user_profile[17], $user_profile[18] and $user_profile[19] are the 4 custom profile fields, in which #16 = custom profile field 1 and so forth.
First, make sure that you select option field in the registration settings in your control panel of the custom field you wish to use. Then enter your info you want the user to see in the text area. All you have to do is match the $user_profile # with the custom field # and stick it where you want. Example: If you want to use Custom Field #1 and have it displayed under the user's name on topic pages then it could look like this:
Find:
$user_public_name
Add Under:
$user_profile[16]
This will work with plain text but if you want something like custom font colors or images then you need to do extra coding. I hope this helped!
THANKS!
PrimeTime