This chart by Shea Strauss, a writer and graphic designer in New York City, first appeared on Playboy in 2014.
It resurfaced on Reddit a few months ago and still hasn't lost its relevance.
So, the chart lays down two conditions under which you can catcall someone.
First, if the ‘she’ you are catcalling is, well, a cat. The second condition is if you and the person you wish to catcall have consensually agreed to catcall each other.
It’s that simple.
If you weren't aware, catcalling is a form of sexual harassment.
An extensive 2015 study found that catcalling happens to most women between the ages of 11 and 17.
A staggering 84% women surveyed for the study said that they experienced street harassment before they turned 17.