FOCUS Enhancements 3.2 - Manual (Page 160)

External Control Commands
146
Reject “Stop” (RJ)
Command:
Stops playback and resets the file pointer to the head of the playlist
(equivalent to a stop button on a DVD or CD player).
Format:
RJ<CR>
Response:
R<CR>
Examples:
RJ<CR>
Stops playback and resets playback pointers to head of playlist.