Yesterday I got an application form to join an organisation I never thought I'd need membership of.
One of the options listed on the application form for payment of the membership fee is "Postal Order". They also list debit and credit cards, cheques, etc, but no PayPal or other modern yokes. Once you cross the initial hurdle of joining, you may subsequently use cards to renew an existing membership, but not as a newbie member.
Passing the post office today after leaving the motor factors, pharmacy and grocery shop, I stopped off to enquire. The postmistress showed me the book of what she called postal orders and bet me pocket-change for the poor box that she's identify the organisation I was joining, based on the need for a postal order to join and its value. They looked like what I remember as postal orders, ordering foreign stamps and suchlike from a philatelists in England. I told her the value and she got it in one! I paid up of course, looking far from pleasant.
Riddle me that then oh wise ones, mere terminology conflict or stuff from the past just hanging around?