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.