This is a new thing on STEEM, @hatoto. Certain groups have formed to have them now and they upvote people who get involved. I do not know too much about really. I am only using the tags for groups I am a part of if they ask.

You can see a list of them here:

https://beta.steemit.com/communities

For whatever reason, only steemit is giving full info. I think other dApps will soon catch up.

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