Error message

Deprecated function: Methods with the same name as their class will not be constructors in a future version of PHP; GeSHi has a deprecated constructor in require_once() (line 915 of /var/www/davidherron.com/sites/all/modules/libraries/libraries.module).

Use a 'Sources' vocabulary to categorize the blog directory

Define a vocabulary, Sources, and assign it to the Feed content type. You can configure the vocabulary any way you like. Mine are configured as 'Tags' vocabularies but if your user base doesn't grok specifying good quality keywords perhaps you should use a predefined vocabulary and set up some terms.