If you do look at perhaps every third, or even just a couple applications in any of our servers app' threads, you will find both players who understand reference, and yes, there are also Many players / applicants who fail to understand reference.
However: From what I have seen, much of these players (Who do not give references / understand it), after applying for Trusted / any staff position, and are declined, seem to leave the community or "vanish." Perhaps they return at a later date, sometimes they may go to a different community, we can never know. Some of these players also do not tend to fill out the entire Staff Application, and merely ask to be trusted.
I know your goal for this idea is simply to confusion among players who apply, even if it is a small amount of confusion destroyed...
Even if we do change reference, there will always be applicants and applications that still do not understand the word / definition / explanation, and we cannot fully stop that.
If it's not broken, then we don't need to fix it entirely. Reference is a highly reliable word for us in Blocktopia, as is in many other communities / the real world. I agree, that the most effective means to reduce this confusion is to possibly add a short explanation to reference.
EDIT: Also-----
Supporting Staff sounds like the supporting actors / crew in a film, game-production, or etc. You can have staff who support you, but don't necessarily are / want to reference you to become staff. When we explain to players on how to become trusted / staff, we tend to encourage them to strive for staff if they really like the community and want to make a difference in it and support it. Will players get confused by "Supporting Staff" by staff who merely encouraged them, which indeed sounds like support from them but is not entirely a reference? Most likely.