Have To Kiss Off this client.  Oh, wait, maybe this

What Does HTKO Mean? HTKO stands for High Tax Kick Out. It is a provision of the tax code that applies when the effective tax rate for foreign source income allocated to the passive category exceeds the greatest United States tax rate.

I've never seen it either, but it probably relates to the question someone asked a couple days ago, about why the 1116 wasn't allowing all of the foreign tax paid.  She was convinced it was a software error.  But no, if the other country is charging a 30% rate on dividends that are taxed here at only 12%, if at all, then you don't get all the credit.  Unless you can use the $300/$600 de minimis exception, which I wonder how many people do.  How much are we talking about here, anyway?