958 days after introducing it officially in Tiger, Apple finally introduced documentation for NSTokenField (what they had before was a class reference, which is well and good, but when you have guides for almost every control, that becomes the actual documentation threshold).
Good news for those who want to implement one of the most unexpectedly finicky controls in Cocoa. No good answers about the actual issues (like problems with the binding not firing when dragging and dropping in some circumstances), but most of that has workarounds.
And hey, that “Token Fields at a Glance” portion. More of that.