I present an overview of my catalogue of Galactic supernova remnants (SNRs), which currently contains 274 objects. The selection effects that apply to the identification of SNRs are discussed, and the limitations that they impose on statistical studies. The selection effects mean that young but distance SNRs (i.e. those with small angular sizes) are easily missed from current catalogues. One such young but distant SNR which is known is G1.9+0.3, and I will discuss some recent radio and X-ray observations of this remnant, which show it is only 150 years old at most, and is the youngest knowb Galactic SNR.