The CRA recently wrote a letter in French on whether charitable foundations are allowed to make gifts to section 501(c)(3) US charities, because of paragraph 7 of article XXI of the U.S. Tax Convention?  The CRA answered no.  Their reason is that American charities are not deemed to be qualified donees under paragraph 7 of article XXI of the Canada-U.S. Tax Convention.

Here is a copy of the CRA letter on whether a charitable foundation is allowed to make a gift to a US charity [in French].

Here are a number of other CRA letters that deal with article XXI of the Canada-U.S. Tax Convention.