What is the deal with the long string of numbers in comments in reddit recently?

Is it related to the dark web or onion sites? I have only recently started seeing it being used.

For example, a post would ask if anyone has seen a picture of a particular tree or something. And the comments would be Three or four different people each listing long strings of numbers that are different from each other. It reminds me of security key numbers.

The example below isn't asking about a picture and it's still there.

https://imgur.com/gallery/vPv8X59

Adding NSFW because the screenshot for an example is from a NSFW subreddit.

Edit: fixed spelling and added context