Where does the sort indicator look?

Question

Design

There is a table. It is permissible to sort the contents of this table by some columns.
On the layout, the sorting direction is indicated by an arrow, but, unfortunately, there is no indication of where, in what order, the arrow "looks".
What is correct: "up" - A-Z (1-9) or "up" - Z-A (9-1)?

Answer 1

Look, for example, in Excel. A-Z down arrow. Z-A up arrow.