<div id="chart"></div>
<script>
$("#chart").kendoChart({
    series: [{
        data: [1, 2, 3]
    }],
    yAxis: {
        notes: {
            position: "left",
            data: [{
                value: 2,
                label: {
                    text: "Important value"
                }
            }]
        }
    }
});
</script>