  We update the systematic studies of circular polarization in integrated pulse
profiles by Han et al (1998). Data of circular polarization profiles are
compiled. Sense reversals can occur in core or cone components, or near the
intersection between components. The correlation between the sense of circular
polarization and the sense of position angle variation for conal-double pulsars
is confirmed with a much large database. Circular polarization of some pulsars
has clear changes with frequency. Circular polarization of millisecond pulsars
is marginally different from that of normal pulsars.
