This sounds like a very human initiative. I couldn't help but recall the time I cried my heart out due to emotional pain. I didn't realize that I would reach a point that I almost ran out of breath as tears flow out. And I wasn't even a kid then. I was a full grown adult just left scathed by life happenings. But in the end, when I look back, I realized that not all of them were cried in vain. Each tear has a corresponding gift - valuable lessons in life.

Proof of tears

Now, I'm sharing this because the possible proof of tears are the learning or realizations we had in the process. After that, you'll be a better individual who can provide counsel or guidance to those who are going through a similar dilemma. Hence, the proof of tears maybe given for those who are able to help out others or in any way touched that person's life.

A mission concept

Another idea I have a mind is that there are delegates, let's call them "harvesters of tears" who will be eager to listen to people who have shed tears, and they will do the processing to extract the gems out of these tearful experiences via tips, advices and/or collection of "how tos". ExamplesI are "How to cry over spilled milk". It's a crazy idea. I'm actually not sure whether I got the concept right, but these are the thoughts running in my mind.

To end, here's a photo of me crying over some spicy Korean noodles. Cheers!