Is Tale of Fairy Ice Trail Considered Canon? Well, is that manga considered canon? I heard that Hiro Mashima praised it as being very good, but does he also accepts it as canon?

Edit: The Key of the Starry Sky arc are not in the manga, yet Mashima-sensei considered it as canon. So, considering this fact, does Hiro Mashima consider this series as a canon as well?
I don't think so, I've searched Fairy Tail Wiki and found this:


  Tale of Fairy Tail: Ice Trail (氷の軌跡, アイストレイル, Aisu Toreiru) is a Japanese manga series by Yusuke Shirato and a spin-off of Hiro Mashima's manga series Fairy Tail.


If it's a spin-off I don't think it's canon