This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
x-ms-aria-flowfrom property specifies the id of the previous element in an alternative reading order, allowing assistive technology to override the general default of reading in document source order. The property serves to define element relationships utilizing ARIA relationship attributes and the
This proprietary property is specific to Internet Explorer and Microsoft Edge.
x-ms-aria-flowfrom property value uses an ID selector to define which previous element the reading order will flow from.
<div tabindex="0" class="foo" id="element2" role="option" aria-posinset="1" aria-setsize="15" aria-flowto="element8" x-ms-aria-flowfrom="element5">