You coloured headaches. But it is not a requirement for the Canadian Case Definition. Not sure if you noticed this - in any one category, the person doesn't have to have all the symptoms. Well, the criteria give various ways to satisfy criterion #3: Well, whether you not rate him, other people may be interested in the fact that in a published study he reported that 3/23 of those who satisfied the Canadian criteria did not satisfy the Fukuda criteria. There is a term for this, criterion variance (?), where different people can interpret criteria in different ways. I'm not so interested in the issue of how many might have the Canadian criteria who don't satisfy the Fukuda criteria. (I'm more interested in the claim that most people who satisfy the Fukuda criteria don't have PEM - the vast majority of research in the field has been published using the Fukuda criteria at least since it was published).