You can use cellattr attribute in the colModel for a column to set custom tooltip. For example
cellattr: function () { return ' title="my custom fixed tooltip for the column"'; }

define the attribute as a fixed text. I use such form for grid having many checkboxs. In the case I set just the column title as the tooltip.

Another more full form can be

cellattr: function (rowId, val, rawObject) {


I wrote you in the previous answer that cellattr

PawelRoman said:I was unclear, sorry. Imagine I have a table with 3 columns, In the first row, cell values are “A”, “B”, “C”, I pass these values in XML they are redered OK. Now, i want to have a tooltip when hovering over a cell “A”, and the tooltip content must be “D” (which as you see has nothing to do with ANY cell data). How do I send this “D” value to the grid? Of course it is a dynamic value thet I prepare on a server side, not a static 'd' letter. Do I have to have an extra hidden column for it or something like this?

Do something like this:

loadComplete: function (data){