@CharizardOnABudget asks
my card just has letters and numbers, no 14/100 thing. Did I find something unofficial?
Jeff answers
Not necessarily. Numbering varies across products and eras, including promo series. I'd copy the whole identifier exactly and look for a matching checklist. Don't fill in a missing slash or assume the letters are irrelevant; that little prefix may be the most useful part.
— Jeff, infinitepulls.com