The IAU Working Group on Reference Systems (WG) was founded by a Commission Resolution passed at the XXth General Assembly in Baltimore in 1988. Since most, if not all, participants in this meeting are familiar with that resolution, it will not be discussed here. Background material may be found, for example, in Highlights of Astronomy, XX General Assembly (1988, Ed. D. McNally). Particular attention is called to the reports by B. Morando, R. Duncombe and J.A. Hughes (pp. 482-500) which were given as part of the Joint Commission Meeting, Towards Milliarcsecond Accuracy, chaired by P.K. Seidelmann. This short presentation will provide a description of the current state of affairs of the WG, which is chaired by the speaker.