For 
in 
Here's how Google defines this word...
be entitled or appointed to act or speak for (someone), especially in an official capacity.
I would say that the parenthesis part in the definition should also include the word something like an idea or a cause or an organization. You can be a representative of Freedom or Church or Boxing Association.
Having expanded this definition in this way, a couple of days ago I saw a full-fledged representation of an American Cancer Society that I'd like to offer to your attention. Hope you'll enjoy it. )
