Dear SIGCIS members I'm writing -- inevitably, far too close to the deadline -- to gauge whether there is interest in offering a symposium submission to the 25th International Congress of History of Science and Technology in Rio de Janeiro, Brazil, 23-29 July 2017, <http://www.ichst2017.sbhc.org.br/>. This is the successor to the 24th Congress held in Manchester in 2013, for which I co-chaired the Local Organising Committee and which was the single largest conference in the field to date, with over 1750 participants. The 2013 programme was strong on computing and related themes -- see <http://www.ichstm2013.co.uk/programme/guide/m/discipline.html#a3> -- and included a mathematical, algorithmic and machine-focused symposium, organised by Maarten Bullynck, Liesbeth De Mol and Marie-José Durand-Richard; a symposium on COMECON technology, put together by Helena Durnova and Slawomir Lotysz for ICOHTEC (whose annual meeting occurred as a satellite to the Congress, as will again happen in Rio); and a symposium on computing applications in various contexts which I organised along with Miguel Garcia-Sancho. The Congress has a more global reach than most forums in the history of science and technology, and tends to be inclusive in its programming selection. There will be a separate call for stand-alone papers, but the call for symposia closes relatively soon, on Saturday 30 April. A "symposium" in Congress parlance is a 90-minute thematic session, or group of linked sessions (the largest symposia run for four sessions a day over several days!) consisting of papers and, optionally, commentaries. The symposium call does not require individual paper titles/abstracts, or a definite list of contributors, but does require an indicative contributor list and a short general abstract. One inviolate rule is that the organisation of the symposium must be a collaborative effort between at least two contributors representing different countries. If anyone is interested in contributing or collaborating, I'd be grateful if you would let me know directly. (I'd also be interested to hear news of any proposals for Rio which have already been settled, whether for the Congress or ICOHTEC call.) All best James