A sci fi book or short story (read in the 80s): some people from our time/Earth ended up in the future (or another planet). The two main protagonists (guy and girl) recognize/identify each other by the marks of chickenpox vaccination on their forearms.
I think I recall in George Orwell’s book 1984 a scene where Winston Smith and his lover compare small pox vaccinations. Hope this helps.
Actually, in thinking about it, it might be Brave New World by Aldous Huxley. Almost certainly a smallpox vaccine mark, not chickenpox.
Thank you !!! This gives me a reason to re-read 1984 For some reason I thought it was from somewhere in Lem or Azimov, but your version is very intriguing, about the “Brave New World”. I can’t say I distinctly remember reading it, but it’s been about 30 years, so the memory is not as fresh:)