What I referred to as the categories pages are indeed the index pages for the various categories in the categories box (e.g., index.php/cPath/21, index.php/cPath/22, etc., for as many categories as are in the box) I'm not sure Ken, why you say the categories box is irrelevant and if the irrelevance pertains to the index.php/cPath/x pages as well. Like the products_info.php pages, the title and meta tags for the index.php/cPath/x pages use the title of the respective categories by default; however, unlike the products_info.php pages the description and keywords can't be modified via admin/header_tags_edit.php. How to modify the description and keywords on the index.php/cPath/x pages is the question.
Although it made common sense to me to refer to the index.php/cPath/x pages as "categories pages", I do understand why, when there is no such thing as a categories.php page, it's necessary to be more precise.