How many varieties are there, exactly?

Every Saturday, a bunch of lady-friends come to the library to knit together. They don't have any affiliation with any library program, they just come together and use the library as a meeting space. They range in age from 20 - 50. The group consists of lots of friends of friends, and over the years has become quite a mix of people, who probably don't see each other outside of this knitting group. This past Saturday, I was putting away some book near where they were sitting and overheard:
Knitter 1: Here comes a homeschooling mom.
Knitter 2: So?
Knitter 1: A homeschooling mom of the denim jumper variety.

Edit: I've been informed that the nomenclature of the denim jumper variety homeschooling mom should be credited to www.thepioneerwoman.com , who is, herself a homeschooling mom, but of a different species.