/msg
Message
Sends a message to a person or a channel without leaving where you are.
Where you type it
In the Slack message box.
Add
@someone or #channel, then your message.
Example
/msg @dana the deck is in the shared folder
A few built-in commands (like /archive, /rename, /remove) can be limited to owners and admins. A real command built into Slack, checked against its own help pages in November 2026. Official help page