IAccessibleText::get_characterExtents() is supposed to return the character extents (visible location) of one or more characters in a text element. Typically, this is called once per character on the line if a screen reader/magnifier wants to get the screen position of each character so it can highlight or magnify each character as the user cursors along the line (using the screen readers virtual cursor position). 

This works for text that is completely LTR (e.g. English) or text that is completely RTL (e.g. Hebrew).

If the text element contains a mix of LTR and RTL rendered text, get_characterExtents does not return the correct bounding rects for each character. Bounding rects are returned, but the order is wrong - it does't match the order of the characters returned in the logical text string from IaccessibleText:get_text().