/indra/newview/skins/default/xui/en/floater_notifications_console.xml

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<floater
 legacy_header_height="18"
 can_resize="true"
 height="500"
 layout="topleft"
 min_height="50"
 name="notifications_console"
 help_topic="notifications_console"
 single_instance="true"
 title="NOTIFICATIONS CONSOLE"
 width="500">
    <combo_box
     follows="left|right|top"
     height="18"
     label="Select notification type"
     layout="topleft"
     left="2"
     name="notification_types"
     top="22"
     width="440" />
    <button
     follows="right|top"
     height="18"
     label="Add"
     layout="topleft"
     left_pad="3"
     name="add_notification"
     top_delta="0"
     width="50" >
        <button.commit_callback
         function="ClickAdd" />
    </button>
    <layout_stack
     bottom="495"
     follows="left|right|top|bottom"
     layout="topleft"
     left="5"
     orientation="vertical" 
     name="notification_channels"
     right="-5"
     top="42" />
</floater>