Robopol: Optical polarisation monitoring of blazars
  The RoboPol program has been monitoring the $R$-band linear polarisation
parameters of an unbiased sample of 60 gamma-ray-loud blazars and a "control"
sample of 15 gamma-ray-quite ones. The prime drive for the program has been the
systematic study of the temporal behaviour of the optical polarisation and
particularly the potential association of smooth and long rotations of the
polarisation angle with flaring activity at high energies. Here we present the
program and discuss a list of selected topics from our studies of the first
three observing seasons (2013--2015) both in the angle and in the amplitude
domain.
