Add this to your CSS and the moderator legends are gone.

Code:

.h3, h3 {
    display: none;
}

Enjoy!

that will delete any and all h3 elements in your forum. So that is an incorrect code. Plus not all forums use this styling.

phpbb2 = taking action inside the templates alone since there is no class or format

punbb = taking action inside the templates as well finding this code

phpbb3 = using a javascript code since there is no template editing. The div that contains the moderator legends has no class so can not be selected very easily.

Invision = I have yet to figure out invision since I don't use it

Code:

<p>{LEGEND} :&nbsp;{GROUP_LEGEND}</p>

before you go ripping codes Boyka you should probably really read into it. As I found the post you got this from and SLG as states to add a p{display:none;}
which again will make all p elements disappear. Ignorant code really since like I said it's getting read of all elements of p and h3. and with the class of .h3 .

As well as the OP who asked the question you ripped this from has phpbb3

sorry about that