I have never heard anyone speak about it.
And I learned it from women.
If you notice any woman across the room, bar, on street don’t look at her directly, rather look to her left, up or right in such a way, that you can see her from your peripheral vision. Then wait for her to look in your direction (you can make that out from your peripheral vision). The moment she looks in your direction, that moment look directly in her eyes with a mischievous smile. As if you have caught her looking at you. She will look away and come back looking at you if she is interested.
I have learned one thing about women. They need space, and you looking around her and not at her directly gives her that space to look at you.
Unless women is ovulating, they won’t look at a man if requisite space is not given to them initially.