Don't know if it still works the same way, but "rubber stamping" used to be real - everybody would stamp a document with their 'hanko' [0] (name stamp). Those who were not completely on board would make their stamp at a slight angle.

[0] https://en.wikipedia.org/wiki/Seal_(East_Asia)#Japanese_usag...

Thanks, interesting :)

Sounds the same as ignoring the disagreement, and a bit remembering who disagreed.