Discord recently added the ability to put “guardrails” around spoiler text to mark it up. E.g.
The film reveals that ||the bad guy is actually his father||.
Discord uses a flavour of Markdown in chat conversions; the addition of guardrail syntax here makes sense since it represents something. Perhaps it could be extended into block syntax like this:
|||
Big spoiler here.
|||
In any case, an inline spoiler syntax would be useful in chat conversations and comments systems, perhaps even more so than a block spoiler syntax. The Discord inline spoiler syntax is bit easier to remember than the !>spoiler<! syntax proposed earlier as it doesn’t require remembering the specific order of the opening/closing characters, plus the characters feel more meaningful.