show multiple categories with “AND” condition?

Hello,

I was wondering if something like this:

[blog category=”25″ category=”37″ show_author=”false” show_content=”true” show_full_content=”true” show_category_name=”false” show_date=”true”]

Means “show blog entries where the category is 25 AND the category is 37”

or
“show blog entries where the category is 25 OR the category is 37”

?

From what I’ve seen, it looks like an “OR” when I really want an “AND”.

Thank you,
Peter.