  We present an analysis of all available time-resolved photometry from the
literature and new light curves obtained in 2013-2014 for the old nova RR
Pictoris. The well-known hump light curve phased with the orbital period
reveals significant variations over the last 42 years in shape, amplitude and
other details which apparently are caused by long-term variations in the disc
structure. In addition we found evidence for the presence of superhumps in
2007, with the same period (~9% longer than the orbital period), as reported
earlier by other authors from observations in 2005. Possibly, superhumps arise
quickly in RR Pic, but are sporadic events, because in all the other observing
runs analysed no significant superhump signal was detected. We also determined
an actual version of the Stolz--Schoembs relation between superhump period and
orbital period, analysing separately dwarf novae, classical novae and nova-like
stars, and conclude that this relation is of general validity for all
superhumpers among the cataclysmic variables (CVs), in spite of small but
significant differences among the sub-types mentioned above. We emphasize the
importance of such a study in context with the still open question of the
interrelation between the different sub-classes of CVs, crucial for our
understanding of the long-term CV evolution.
