...clearly that's a content type validator. A zing is actually just a chat message. Take a look at the zing type definition in https://github.com/urbit/urbit/

...clearly that's a content type validator. A zing is actually just a chat message. Take a look at the zing type definition in https://github.com/urbit/urbit/blob/master/urb/zod/main/sur/zing/gate.hook https://github.com/urbit/urbit/blob/master/urb/zod/main/sur/... $% [%hola p=path] $: %mess p=path $= q $% [%do p=@t] [%exp p=@t q=tank] [%say p=@t] == == == Which (ignoring the crazy syntax) is either an initialization (an %hola), an action (a %do, like /me in IRC), an embeded Hoon expression (an %exp, which is a [code output] pair), or a message (a %say). @t is just a string type. sur/zing/gate/hook defines the type, mar/zing/core/hoon uses sur/zing/gate/hook to validate untyped data received over the network.