What a weird and unwieldy spoiler syntax, I wonder where Lemmy grabbed that from.
Specifically, the tag start condition is ::: spoiler, which doesn't match any markdown syntax I've ever seen, it requires having a title, and it doesn't work in the middle of a line at all, you have to make it an entire block.
So instead of The sky is >!blue!< and not green or something like that, you have to write:
The sky is
this spoiler title part is required
blue
and not green
The sky is
and not greenthis spoiler title part is required
blue
