Subscribe to change, the event textinput actually emits Three examples subscribed to submit. textinput emits one event, change; submit is only a code comment (textinput.go:122), never a wire name. They passed the executable example checker because sub accepts any word and never validates it against the type -- the one class of error that checker cannot catch, and the reason it is worth fixing in the protocol. Also drops the describe line counts from two pages. Those move as types are added, and the shape of the output is the part that stays true.
Add the Introspection page What describe streams and why the wiki keeps deferring to it. The five statement kinds with a real line of each, what of= and enum= and the virtual flag carry, and the two properties the scheme rests on: unknown statement kinds are ignored, so hosts may add and clients may ignore; and encode-decode-encode is byte identical, which is what lets a tool read a live host or a local registry without being able to tell them apart.