Check out this strange pic:

https://vintagespace.files.wordpress.com/2011/04/ivan-ivanov...

"MAKET" means dummy or doll. This is the dummy pilot used in a test flight. The word is there so that any well-meaning farmer who finds the craft won't start cutting anything open in a rescue attempt, possibly destroying test data.

I've also seen, but cannot find online, pictographs on soviet spacecraft meant to inform possibly illiterate rescuers that real people are inside and probably need help. Similarly, look at any plane with ejector seats. There are usually signs or diagrams explaining how to pop the canopy and even trigger the ejection seat of a crashed plane (usually by means of a rope).