C'T: DVD+R & CAV = ๐Ÿ˜•

In their latest DVD article, the Cโ€™T has stated something without explanation which I canโ€™t get sense into:

They claim that DVD+RWs, written in CAV mode, could not be played in DVD settop players at all. They also claim that DVD+R does not even support CAV because of this problem.

=> Why should CAV writing prevent settop players from reading DVD+RW discs :confused: What would the difference (technically) be between reading a CLV written DVD+RW / a CAV written DVD+RW?