thanks – FWIW, tooltip seems to be somewhat incompatible with grid.   on a slightly larger grid, the tooltips would take several seconds to open, probably because of the grid javascript overhead.

so i am going with title instead.

it would be nice if a future version of grid had a way to insert text information in a notes field like many spreadsheets have, where you see a little red triangle marker in the lower-right corner of the cell indicating there are notes associated with this cell.