In what I've been doing, I usually would change it as follows...

<!--[/if]--><!--[if(Custom1)]--><b>Custom1: </b> <!--[Custom1/]--><br>

would change to:

<!--[/if]--><!--[if(Custom1)]--><b>NEW NAME:</b> <!--[Custom1/]--><br>

This would display as "NEW NAME: <content of Custom1 field>"

I don't know if this will be any help at all, I'm just guessing... but that's what I've done on mine.