If you’d like to have an example of what a Custom Layout Update code might look like to use in Magento in the Category admin section, see the code below:
<reference name=”left”><block type=”catalog/navigation” name=”catalog.vertnav” template=”catalog/navigation/left.phtml” /></reference>
This code adds left.phtml in the left column, underneath any other items in the left column of your Magento site. If you want it above, a simple trick is to add “before=” to the code so it looks like this:
<reference name=”left”><block type=”catalog/navigation” before=”catalog.leftnav” name=”catalog.vertnav” template=”catalog/navigation/left.phtml” /></reference>
Of course, you need a file, left.phtml residing in your catalog/navigation directory of your theme directory, but, that’s another post.
Here is a great example of a left column layout update on a site we did for Summit Equipment, a site devoted to specialty tools and equipment.