OpenMW/files/mygui/openmw_tooltips.xml

<?xml version="1.0" encoding="UTF-8"?>

<MyGUI type="Layout">
    <Widget type="Widget" layer="Popup" position="0 0 300 300" name="_Main">

        <!-- Simple text-only tooltip -->
        <Widget type="Widget" skin="HUD_Box" position="0 0 300 300" align="Stretch" name="TextToolTipBox">
            <Property key="Visible" value="false"/>
            <Widget type="EditBox" skin="MW_TextEdit" position="0 0 300 300" align="Stretch" name="TextToolTip">
                <Property key="WordWrap" value="true"/>
                <Property key="Static" value="true"/>
                <Property key="TextAlign" value="Left Top"/>
            </Widget>
        </Widget>

        <!-- Dynamically constructed tooltip goes here -->
        <Widget type="Widget" skin="HUD_Box" position="0 0 300 300" align="Stretch" name="DynamicToolTipBox">
            <Property key="Visible" value="false"/>
        </Widget>

    </Widget>
</MyGUI>