Alesco suffers NZ optional convertible notes blow Jack Grocott December 12 2011 X LinkedIn Email Show more sharing options Copy Link URLCopied! Print X LinkedIn Email The New Zealand Inland Revenue Department (IRD) today won a landmark tax avoidance test case on the use of optional convertible notes (OCNs). Unlock this content. The content you are trying to view is exclusive to our subscribers. To unlock this content: Take a Free Trial or Login