In September, 2018 we announced that Dynamic Array support would be coming to Excel. This allows formulas to spill across multiple cells if the formula returns multi-cell ranges or arrays. This new dynamic array behavior can also affect earlier functions that have the ability to return a multi-cell range or array.
Below is a list of functions that could return multi-cell ranges or arrays in what we refer to as pre-dynamic array Excel. If these functions were used in workbooks predating dynamic arrays, and returned a multi-cell range or array to the grid (or a function that did not expect them), then silent implicit intersection would have occurred. Dynamic array Excel indicates where implicit intersection could occur using the @ operator, and as a result, these functions may be prepended with an @ if they were originally authored in a pre-dynamic array version of Excel. Additionally, if authored on dynamic array Excel, these functions may appear as legacy array formulas in pre-dynamic array Excel unless prepended with @.