docs: mention that functions cannot be serialized to JSON
@@ -638,6 +638,8 @@ type ValidateOpts struct {
BypassDestinationValidation bool `json:"bypassDestinationValidation"`
// CheckTransactionCode allows for custom validation of TransactionCode values
+ //
+ // Note: Functions cannot be serialized into/from JSON, so this check cannot be used from config files.
CheckTransactionCode func(code int) error `json:"-"`
// CustomTraceNumbers disables Nacha specified checks of TraceNumbers:
