Why do these two things work: 1)\defineXMLnested [td] [rows=1,cols=1] {\bTD[nr=\XMLop{rows},nc=\XMLop{cols}]} {\eTD} (in conjunction with '<tr><td rows="2">Gene product</td><td cols="3">HPM tag</td><td rows="2">TAP tag</td><td rows="2">mod. TAP tag</td><td rows="2">Frequ. in ref. set</td></tr>') 2) \bTR[bottomframe=on,rulethickness=0.3pt]\bTD a \eTD\bTD b \eTD\bTD b \eTD\bTD c \eTD\eTR% But this doesn't? \defineXMLnested [tr] [bottomframe=off,rulethickness=0.3pt] {\bTR[bottomframe=\XMLop{bottomframe},rulethickness=\XMLop{rulethickness}]} {\eTR} together with '<tr bottomframe="on"><td rows="2">Gene product</td><td cols="3">HPM tag</td><td rows="2">TAP tag</td><td rows="2">mod. TAP tag</td><td rows="2">Frequ. in ref. set</td></tr>' Thanks, Joh