According to the wiki and my experience there is no way to do this in the classic UI in OH 1.7.1. If you’ve seen this on videos perhaps it was talking about a third party UI or the OH 2 UI (which I’m not familiar with cannot say whether this is supported).
I have gone back to have a look and it appears the videos may be using ALT Codes to display icons instead of text. Any ideas on how to code in ALT Code to show up in the user interface.
Look up the number for the alt code you care about. Then look up the key combo for entering alt codes on your platform (on Linux it is hold <ctrl><shift>, type “U” followed by the number of the symbol you want, then release. Type this as the label part in your mappings.
rule "PlayerControls"
when
Item playerState received command
then
switch(receivedCommand) {
case "PREV" : squeezeboxPrev("player")
case "STOP" : squeezeboxStop("player")
case "PAUSE" : squeezeboxPause("player")
case "PLAY" : squeezeboxPlay("player")
case "NEXT" : squeezeboxNext("player")
}
end