By default, RapidWeaver inserts the iTunes RSS tags defined in your blog page's Setup... area. These tags are specifically used by Apple's iTunes to to cagegorize your Podcast, describe its contents, assign your Podcast to a channel, and manage other settings.

Blog - Podcast: iTunes Tags

You can add, remove, or change the default iTunes tags by clicking the "Enable Custom iTunes Tags" checkbox and editing the fields on the iTunes tags pane.

TIP: For more information about Podcasting and iTunes, including a complete list of the iTunes tags used by by iTunes, go to Apple's Podcasting and iTunes: Technical Specifications page.

By default, categories are enabled in RapidWeaver allowing you to set a category or classification of your individual blog entries. If categories are not desired, you may disable them by unchecking the "Enable" checkbox. If enabled, you may also choose to display the number of blog entries in each category in the sidebar by clicking the "Show Post Count" checkbox.

Blog - Setup: Categories Tab

You can create additional categories for your blog by clicking the (+) button at the bottom of the categories list and typing the name of the new category. To remove a category, click on its name and click the (-) button. You may also arrange the categories in the list by clicking and dragging a category into a new position.
At the bottom of the Categories pane, you'll find a Separator field. RapidWeaver uses the characters in this field to delineate the various blog entry details such as the datestamp, category, and permalink elements (located below the blog entry's title in your blog). The default separator is a 'pipe' delimiter ('|') with a space character before and after it for balance (e.g. ' | '), but you may use a different combination of characters if desired.