Tamarin:IronMonkey:AVM2Errata
On page 15, "Registers 1 through method_info.param_count holds parameter values coerced to the declared types of the parameters. If fewer than method_body_info.local_count values are supplied to the call then the remaining values are either the values provided by default value declarations (optional arguments) or the value undefined." may be technically correct, but "If fewer than method_info.param_count values are supplied" reads better with "The rest of registers are initialized to the value undefined" added after NEED_REST and NEED_ARGUMENTS clauses.
On page 25, "The number of optional parameters is given by option_count, which must not be zero nor greater than the parameter_count field of the enclosing method_info structure" should read param_count.