With Christmas coming you might want to ask someone to give you the big dog on this topic. 'Cartridges of the World'.
http://www.amazon.com/Cartridges-Wor...s+of+the+world
Take note though the book has its detractors - check the one star comments on Amazon. I think the critics have a point but it is still a tremendous reference on the topic.
And as 44 AMP said there is little reason to some of the cartridge names. They have been developed and invented over the years in many different countries when there were no 'standards' committees or regulartory boards and folks just named them whatever they wanted.