I just attempted to upload a skin with a custom chunk for Minecraft Java edition. The extra chunk was scrubbed at some point before the client downloaded it.
Allowing for valid custom chunks would provide a basic means of "copy protection" for skins. You could create a "made by" chunk to "sign" a skin in a way that most people would not be able to see.
Please allow for custom PNG chunks.
Thank you for your report!
However, this issue is Invalid.
You have posted a feature request or a suggestion. This site is for bug reports only.
For suggestions, please visit the Minecraft feedback site or Minecraft Suggestions on Reddit.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki