The earliest known mention of a Dolphin Council came from 
https://steemit.com/steemit/@underground/announcing-the-creation-of-the-dolphin-council-
There was a later post by me (
https://steemit.com/dolphin/@kabir88/dolphin-council-it-s-time-to-organise-and-make-our-mark
Here is the most recent update on the development of the constitution on how the group would work from
https://steemit.com/dolphincouncil/@niallon11/dolphin-council-draft-constitution
We already have a great core group of steemians discussing how this group should work and the best way for us to coordinate, but avoid the usual pitfalls of centralised governance. The vision is to remain a decentralised collective that come together to coordinate on important issues.
Thank you to the following users who have joined our discord(https://discord.gg/3Bz7a6E) :
@KrNel
That's 934,704 worth of steem power looking to work together. Come join us and together we can provide steem with the community leadership that it needs.