Currently, there's only one option: "This account is utilized by members of a multiple system."As said in a library article, there's multiple systems, median systems and gateway systems.What I have in mind is:
In that case it may be better to change 'Multiple System' to 'Plural System', as I think plural covers all varieties of systems, while multiple is just one specific type of plural system (you may want to confirm this with someone more versed in the terminology).
Echoing Velvet Wings suggestion as simply changing the wording to "Plural System" as its generally used as an overarching term in places. (You could also change it too "Plural system (multiple, median, etc)" is you are concerned systems coming in might be unsure of if to check the box or not.
We love this idea! It would be useful in determining the type of system you're talking to and would possibly keep those who simply mark it to put it on their profile from simply selecting it. It requires more thought.