Show CMS static block on only one specified category page (Magento)

The layout XML code below helps to achieve the above requirement. It will show the static block my-sidebar-1? on right sidebar of category with id 10?. Similarly, static block my-sidebar-2? is displayed on the category page with id 12?.

<CATEGORY_10>
    <reference name="right">
        <block type="cms/block" name="my.sidebar.1" before="-">
            <action method="setBlockId"><block_id>my-sidebar-1</block_id></action>             
        </block>
    </reference>
</CATEGORY_10>
<CATEGORY_12>
    <reference name="right">
        <block type="cms/block" name="my.sidebar.2" before="-">
            <action method="setBlockId"><block_id>my-sidebar-2</block_id></action>             
        </block>
    </reference>
</CATEGORY_12>