2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7368Applications of the thermal-viscous disc instability model to various classes of cataclysmic variable very often require the accretion disc to be truncated. I argue that in most cases this inner truncation must be due to the white dwarf's magnetic field.To appear in: Compact Binaries in the Galaxy and Beyond, IAU Coll. 194, editors E. Sion and G. TovmassianAstrophysicsThe implications of disc instabilities on cataclysmic variable structure and evolutiontext