Dear Developers and All, lpdf.checkedkey routine from lpdf-ini.lua has problems with accessing false boolean values, it returns them as nil. Is it by design or neglect? (I vaguely remember stumbling on this problems before, so there is a chance that I have already got the answer, but have forgotten it.) The minimal demo: \starttext \startluacode local function writebool(bv,text) if bv == true then io.write(text, " true \n") elseif bv == nil then io.write(text, " nil \n") else io.write(text, " false\n") end end local a = {} a["x"] = true a["y"] = false a["z"] = nil writebool(lpdf.checkedkey(a,"x","boolean"),"lpdf.checkedkey(a,\"x\",\"boolean\")") writebool(lpdf.checkedkey(a,"y","boolean"),"lpdf.checkedkey(a,\"y\",\"boolean\")") writebool(lpdf.checkedkey(a,"z","boolean"),"lpdf.checkedkey(a,\"z\",\"boolean\")") writebool(a.x,"a.x") writebool(a.y,"a.y") writebool(a.z,"a.z") \stopluacode TEST \stoptext It results in the following relevant output lpdf.checkedkey(a,"x","boolean") true lpdf.checkedkey(a,"y","boolean") nil lpdf.checkedkey(a,"z","boolean") nil a.x true a.y false a.z nil Note that false value was read by checkedkey as nil. Sincerely, MIchail