I know that some makers, such as Zegna, Oxxford, etc- actually write "suit", "jacket", "sc" etc. on the suit tags to indicate whether it's a suit or blazer/sport coat.
As with Canali, you just have to do a search on the model number.
I know people like to say that the fabric and styling is a dead give away, but that's not always the case. I've seen lots of sport coats from high-end manufacturers that are identical to the coats of their suits.
Hell, my navy...