Does Canada qualify as Democratic socialists?
You can pretty much kick them in or out of the category as you please. There's no generally accepted definition and I've seen it used much differently by different scholars.
Typically, they allude to certain elements for a description:
Ex: If a society exhibits the following elements (x, y, z) we'll call it capitalist. If they exhibit (g, r, t) we'll call it socialist (or whatever). Then it gets sticky when you see element z in a society that's being defined as g, r, t and vice versa.
It's complicated to define governments and even attributes of various systems and classify them as one or the other.
I try not to get involved in this type of bullshit cause it just goes around and around in circles. But generally, if the reader can understand what you're trying to convey, it really doesn't matter.