A problem for developers doing sites where a lot of tabular information must be displayed is that the data tables get to big for the page and the user has to scroll the data. When they do that, the headings of the table scroll off the screen. The solution would be to have just the body of the table scroll with the headings remaining fixed. Unfortunately it is not easy to implement and most attempts end up with a page that is easily broken. The best still don't look or work quite right.