Table cells can have a col- or rowspan value of 0, which I understand means all remaining columns in the column group (or rows in the row group) are spanned: http://www.w3.org/TR/html401/struct/tables.html#adef-colspan AFAIK only Firefox supports this value today, and probably no web sites will be using it in the near future.

Problem is I'm writing a generic javascript that checks if a table's cells span other columns or rows (=span values larger than 1) or not (=span value 1). I will not write the actual HTML table myself, and will not be able to adjust the script to various tables. To make my script future-proof, should I check for the value 0 as well, and if so what should the script do with it?

I'm thinking of letting the script change a value of 0 to the total number of remaining columns/rows in the colgroup or rowgroup (which should produce the same span as the 0 value), as a workaround for browsers not supporting the 0 value. Could such a workaround create problems?