The message on the back of a photograph may become more valuable than the frame.

Provenance outlives presentation. The frame is the expensive part now and the pencil on the reverse is nothing, but in forty years the frame will be a frame and the two lines in somebody’s hand will be the only reason anyone knows who these people were, or when, or why they were laughing. Context is what makes an image survive its subjects. Almost nobody writes it down, because at the time everybody present already knows.

Turn over the photographs you have and write on the ones that say nothing. Names, place, year. Ten seconds each, and it is the part your family will want.