Dear Hans, Many thanks for implementing space=small in \setupunits. It works nicely for me. However in the latest beta, Hertz is typeset as hz not Hz. It looks like the problem is line 154 of phys-dim.lua (it was typeset correctly a couple of days ago). Also the symbol for lux (line 198) should be lx [2]. Degrees, minutes and seconds of arc (also degrees Celsius) are an exception and are not supposed to have any space between the digits and the degree symbol [1], so to be correct, I think Context should by default veto any space between digits and numbers, in these cases only. BTW, NIST has a handy reference for anyone typesetting physical quantities [1], although the BIPM documentation is the canonical reference. Robin \starttext \unit{1 Hz} (should be Hz)\par \unit{180 deg} (should be no space)\par \stoptext [1] http://www.bipm.org/en/si/si_brochure/chapter5/5-3-2.html [2] http://physics.nist.gov/cuu/Units/