Raise The Flag And See Who Salutes Meaning

(idiomatic) To float an idea, (or otherwise do some action) to see what response or controversy (if any) it generates, usually as a preliminary step.

Example: 1996, Jo Ann Oravec, Virtual individuals, virtual groups: Human Dimensions of Groupware and Computer Networking, page 312
  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.”