core/homeassistant/components/velbus/icons.json

{
  "services": {
    "sync_clock": {
      "service": "mdi:clock"
    },
    "scan": {
      "service": "mdi:magnify"
    },
    "clear_cache": {
      "service": "mdi:delete"
    },
    "set_memo_text": {
      "service": "mdi:note-text"
    }
  }
}