A hundred years ago, that is what you might have said to a friend when you were going away, and you wouldn't have been referring to any of the things for which we use this abbreviation today.
Picture postcards became legal towards the end of the nineteenth century and this one appeared in 1995 to celebrate their centenary. The publishers, Bamforth & Company, entered the postcard business in 1902 and could have produced both images from stock; they probably took some liberties with dates, for the girls on the left look more like early twentieth century bathers, and daring for their day.
Throughout the entire length of the twentieth century the postcard was in popular use, and it may be that this was the last as well as the first century of which that might be said. It is hard to imagine that anyone will be sending (let alone collecting and delivering) so physical an object in 2099.
One of the most worthwhile of all the projects inspired by the 2000 millenium was the publication of The Postcard Century, which tells the story of the previous hundred years in its own words and images: two thousand picture postcards and their messages give a vivid account of people's daily existence and a glimpse of what mattered to them, pleased them, shocked or amused them via the cards they chose to send and what they wrote on them.
Other Men's Flowers will try to do justice to the book over the coming months, but reading about it and seeing snippets is no substitute for owning it and passing many happy hours devouring its contents.