From photometric observations of the old nova RW UMi ( 1956 ) we have discovered the presence of five sub-orbital periodicities .
The longest period , P _ { 1 } = 54.4 min , always observed , could be the beat period between the orbital period and the white dwarf ( WD ) spin period that we assume to be P _ { 2 } = 33.4 min .
The other suborbital periods could be orbital sidebands with respect to P _ { 2 } and/or correspond to Keplerian resonance radii .
We suggest that in its post-outburst state , characterized by higher \dot { M } , RW UMi is an asynchronous intermediate polar with a truncated accretion disc .
If the magnetic momentum of the WD is \mu _ { 34 } \sim 0.8 , in its quiescent pre-outburst state , the nova would appear as a discless , synchronous intermediate polar .