The Obsidian folks are doing it again: adding more features to Markdown, which itself is not rigorously specified. (See: https://obsidian.md/changelog/2026-10-05-desktop-v1.14.4/)

They've added text highlighting with the following syntax:

==🔴This is a red highlight.==
==🟠This is an orange highlight.==
==🟡This is a yellow highlight.==
==🟢This is a green highlight.==
==🔵This is a blue highlight.==
==🟣This is a purple highlight.==

Surely, this won't cause any problems for people later who want to convert their markdown to another format... like me... (/sarcasm).