  A catalogue of 231 Galactic supernova remnants (SNRs) is presented, and the
selection effects applicable to the identification of remnants at radio
wavelengths are discussed. In addition to missing low surface brightness
remnants, small angular size -- i.e. young but distant -- remnants are also
missing from the current catalogue of Galactic SNRs. Several statistical
properties of Galactic SNRs are discussed, including the
surface-brightness/diameter (Sigma-D) relation. It is concluded that the wide
range of intrinsic properties of Galactic remnants with known distances,
together with the observational selection effects, means that use of the
Sigma-D relation to derive diameters and hence distances for individual SNRs,
or for statistical studies, is highly uncertain. The observed distribution of
bright SNRs, which are thought to be largely free from selection effects, is
also used to derive a simple model for the distribution of SNRs with
Galactocentric radius.
