No comment metadata for app-based filtering

[ross-currie]

As more apps like Zappl and Steepshot start building on top of the Steem blockchain, scenarios are becoming apparent where where there's a need to begin filtering content based on the app it was intended for. Eg, it makes sense for micro-content from Zappl (A small photo with caption, a short microblog/tweet) to only appear in Zappl, and not to appear on Steemit.com

Currently, there's nothing inside the standard, specifically relating to comment metadata that is identified to be used in this manner and so I'm proposing that the standard be amended to facilitate this

Specifically, I recommend the addition of two fields to the comment metadata for the standard:

1. ecosystem: Multi-value field to indicate which apps the comment should be read by. If no value is provided, 'steemit' will be the assumed default (which will make this backwards compatible with the existing comments in the blockchain).

2. appkey: This will be a public key that an app can use to verify whether comments posted to its content ecosystem should be filtered into the app. The authentication mechanism is up to the target app, but the posting app will only ever need to provide a single key with each comment (this single key should be accepted for any ecosystem it's posting to).

The timing seems crucial on this, as we're getting very close to a point where apps will begin posting large volumes of content on the Steem blockchain (Steepshot in Alpha now, Zappl beta in August '17) and if no standard is established we'll have complete and utter mayhem ;)

[ross-currie]

Wrote a Steemit post with a bit more info about the challenge and my justification for the solution proposed above https://steemit.com/steemit/@rossdcurrie/app-filtering-the-steem-blockchain-the-challenge-and-a-proposed-solution

[kellyjanderson]

Further to this concept the standard does not provide explicitly for arbitrary metadata those apps may wish to add. This arbitrary data should have a specified root field, within which third party applications place their name spaced metadata.