Previous versions of this specification required connections to be
closed on version mismatch. This requirement is revoked to allow
interoperability between protocol families / networks.
* identify: Document identify behavior for asymetrical protocols
> Note on asymmetrical protocols: Assume an asymmetrical
request-response style protocol `foo` where some clients only support
initiating requests while some servers (only) support responding to
requests. To prevent clients from initiating requests to other clients,
which given them being clients they fail to respond, clients should not
list `foo` in their `protocols` list.
Question emerged in https://github.com/libp2p/specs/issues/324.
* identify/README: Reword to inbound substreams
