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 ( \sim 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 .