An idea for helping humans and machines understand when a twtxt-feed are using some of the yarn.social extensions by applying a mix of a hash-bang and a DTD to the first line of the txt-file:

```#! DOCTYPE = twtxt (https://twtxt.readthedocs.io) with extension for multi-line and conversation treading from Yarn.social (https://dev.twtxt.net)```

It would be nice if the link to the extension could be to `dev.yarn.social`, `docs.yarn.social` or similar instead of `dev.twtxt.net` to make it less confusing.

@darch https://git.mills.io/yarnsocial/yarn/issues/1157

@marado obrigado 🙏

@lyse i don't have much more than this. But I agree to keep it simple. I like your approach.

@lyse from my POV, both approaches achieve the same, and I'd be happy to see one or the other on yarn generated feeds.

@prologic I like that the information is there to help those reading the feed - automatically (with a client) or manually.

@prologic Come to think about it, I'm more in favor of @lyse 's approach; Make it human readable with relevant links and not do anything specific for the machines. This is almost already the case for twtxt.txt served by yarnd, we just need to add a line to the Yarn.social section explaining about the extensions.