Определение raise the flag and see who salutes в Английский Язык Английский Язык словарь
To float an idea, (or otherwise do some action) to see what response or controversy (if any) it generates, usually as a preliminary step
Much of the discourse on and the spirit of group interaction have an improvisational flavor: we “float trial balloons” in the groups we belong to or “raise a flag and see who salutes.”.