I wonder if it was possible to make a plugin where you can paste text onto signs. There should not be any commands or permissions. My server is 1.12.2.
Pasting it into the sign editing GUI is client sided. It would only be possible with a command or anvil GUI.
I think @alex778c means copying from one sign and pasting to another one. If that's the case, it is possible.
@alex778c It seems like there's a lot of questions about what exactly you mean, could you try rephrasing and explaining it?