Suppose I read a sign in the street headed Psak Din which says that such-and-such a thing is forbidden (these signs never say such-and-such is permitted), with the names of a list of rabbis at the bottom that supposedly agree on this.
Can I ignore it? Should I go to the great effort of confirming that the rabbis really did agree to this? Does it automatically follow that if the rabbis really did agree on this, that I personally have to follow it? Do I have to follow it out of "sofeik" (doubt)?
Related question: Is it permitted to intentionally avoid reading such signs?