This seems like a topic with a lot of potential for semantic differences stemming from point of origin - US or UK, primarily.
Interesting to hear James talk about Fenton's pontils, when I (who knows very little about Fenton, sorry James) have heard that Fenton almost never has them! I've heard people many time exclude Fenton as a candidate for ID because an item has a pontil mark.
Definitions of some of these terms according to my understanding:
In the US "pontil" (pontil mark/scar) refers to the point of attachment, while "punty" refers to the rod. A parison is the small blob of glass just beginning to be blown, before it is worked into final shape. "Blank" is a little harder to define. The most narrowest definition I've heard is, a cooled item that is intended to be decorated by etching, cutting, enameling, etc. Since many items may end up undecorated, though, it is often used less specifically to refer to any item in a pattern (I'm thinking here mostly about American Elegant and Depression glass, e.g. Heisey, Cambridge, etc.). It's also a very common term in rich cut (miter cut, what I call the "sparkly stuff") glass circles, but is used there to refer to a pre-cut glass item, or the shape it would have been before cutting. In the case of figured blanks, it may already have a pattern molded into it that will be further elaborated by cutting.
So a snap=a gadget! Huh! Is the term "marie" used in the UK?
This site has an excellent explanation of different types of pontil scars:http://www.sha.org/bottle/pontil_scars.htm
and its parent page has lots more great info and links, geared toward bottle making, but applicable to other glass as well:http://www.sha.org/bottle/glassmaking.htm
(I notice they call it a "pontil rod," rather than "punty rod")