Hatching (Heraldry)

Just the other day I learnt about the hairy heart emoji in Android 4.4, which was actually misinterpreted from a black-and-white hatched heart in unicode that used the dots to indicate yellow, per this wiki article.

https://emojipedia.org/google/android-4.4/yellow-heart

https://thenextweb.com/news/pink-hairy-hart-emoji

I haven’t seen any references to heraldry in MacPaint/Susan Kare lore, but this certainly reminds me of those patterns and textures.

I know that hatching is also used to describe the texturing on rifle stocks.

As someone who writes about heraldry, I'm happy to see this here. I'm a little surprised, though. What about this is interesting for the Hacker News crowd?