There is an obvious interest in capturing general trends in the structure of phonological systems of the world's extant languages.These may hint at overall design properties of human language, which in turn may have origins in basic human cognitive properties or characteristics inherited from the earliest human language(s).One tool that can be used to study such trends is a broadly-based crosslinguistic database on phonological systems.Four of the principal challenges to providing this will be discussed in this paper, which describes the thinking behind the compilation of the LAPSyD database and draws some comparisons with other somewhat similar projects, such as PHOIBLE, SAPhon and Segrer's African consonant inventory database.