Yamaha MCX-CA15 Owner's Manual page 220

Function keys
4
Press SELECT. When the Function screen appears on the display,
use u/d to select a function.
5
Press SELECT.
The selected function is assigned to the function key that you selected in step 3.
If you select "Favorites", "Client: Timer ON", or "Client:Timer OFF", follow the
procedure below before carrying out step 6.
When selecting "Favorites"
Press SELECT when the confirmation screen appears on the display.
When selecting "Client: Timer ON"
Follow the procedure on page 16 to configure target clients for Client: Timer ON.
When selecting "Client: Timer OFF"
Follow the procedure on page 17 to configure target clients for Client: Timer OFF.
6
Use d to select "OK" and press SELECT.
The MusicCAST server saves the function key settings.
7
If you selected "Favorites" in step 5, follow the procedure on page
15 to select a playback group to assign to the function key.
14 MusicCAST Version Upgrade 1
Cancelling the setting
operation
Press BACK, or move the cursor
to "Cancel" and press SELECT.