At the present moment, there are two annotations:
@Verifier(tx). The variable name in the annotation is required even if the function does not use it.
An annotated function cannot be called inside a dApp script.
# @Callable(i: Invocation)
Annotation of a callable function.
i contains information about the transaction that invoked the function of a dApp.
Annotation of a verifier function.
tx contains information about the transaction or the order that was sent.