The /output-style command has been deprecated. It now shows a message directing users to /config or the settings file. The command is hidden from help output but still works for backwards compatibility.
Evidence
Deprecation handler (search for "/output-style has been deprecated", "Deprecated: use /config to change output style")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeDeprecated /output-style command — use /config instead. Output style is now fixed at session start for better prompt caching
