You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
Slash CommandsArea: what it touches
Bug FixesKind: in v2.1.233,
Bug FixesSection of the release
What
If you pass a custom command an argument whose text contains something like $2 or $ARGUMENTS, that text is now inserted literally instead of being expanded again by the later substitution passes.
Details
Applies to $ARGUMENTS, $1, $ARGUMENTS[n] and named placeholders in a command's prompt.
Each substituted value is wrapped in a private marker character and its $ signs are escaped to a second marker, both removed at the end.
Any of those two marker characters already present in the template or in your argument text are replaced with the Unicode replacement character first, so they cannot be used to smuggle expansion back in.
The final unescape pass now always runs rather than only when an escape was seen.
Evidence
Strings lifted out of the shipped bundle, so the claim above can be checked against them.