I'm surprised they wrote on the edges.
My family was notorious for writing captions right on top of images in old photos. My grandmother took a WW1 portrait and of course in ball point, wrote the info right over the person's image. I asked Mom about that and she said that was just how people did stuff. When Mom put together a photo album of photos from my birth to high school, she wrote locations, dates and people's names right over the very centers of the images as well.
I wanted to scream when I saw that.
But it's clearly something people used to do.
-Lee
Flickr photo set of my On30 layout