I have an org-mode file separated into multiple categories. I know I can create an agenda command that will show only items from one given category, like so:
("a" "Category A items" agenda "" ((org-agenda-category-filter-preset (quote ("+a")))))
and then only items from category A will show up in the custom agenda view.
How can I configure a custom view so it will show items from two specified categories (e.g. "A" and "B")?