Download version 0.3 ‘Weefz’s Show Post Subcategories‘ from the WordPress Plugins Directory (or see below for version 0.4).

Here’s how it works:

1. Unzip the download into your WordPress plugins directory
2. Activate it in the plugins management screen
3. Go to your template editor
4. Within The Loop, add the following tag
<?php wfzShowPostSubcategories('prefix','suffix','separator','parent category id number') ?>
5. Replace prefix, suffix and separators with the text of your choice, keeping it within the single quotation marks
6. Replace cat_ID with the ID number of the parent category

For example, say that you want to show the post’s subcategories of category 5 in an unordered list. Use the following tag:

<?php wfzShowPostSubcategories('<ul><li>','</ul>','</li><li>','5') ?>

I have used this with all versions of WordPress from 2.2.1 to 2.7.0. It doesn’t do anything fancy, so should work with earlier versions.

Disclaimer: This is my first WordPress plugin, so please test it out before installing on a live site. I use it myself right here at One Serving – it drives the links to the “High in” nutrient fields for every food serving size post.

Drop me a comment below with any questions or advice. If you like the plugin, feel free to buy me a beer or healthy juice drink with the PayPal button ;)

Update 8th June 2009: Plugin is now on version 0.4. By popular request, it now allows you to display subcategories without any separator. Just use the following:

<?php wfzShowPostSubcategories('','','','your parent category id') ?>

It’s temporarily available here until I find the time to upload it properly to the WordPress Plugins directory.