What is this new wiki option?

I just responded to a post and noticed that it was posting as a wiki? Is this new? Where is this being saved?

@james1

Our forum is hosted on discourse.org. There is a note about the wiki component here: http://www.discourse.org/about/

I believe the feature you are referring to is the ability to treat your post as a wiki, which means others signed into the community can edit it. I assume that would be useful if you have part of an answer and others could improve or add to it.

Best,

~ Cameron

Interesting; however, I am not sure how I activated the wiki option? It must be new tho since I never saw the extra icon before.