When viewing the b2blogs.php page, you can see the number of the blog.
Very handy to put the blognumber in the stubfile.
To post on a multiblogpage the last posts of a certain category, you need the categorynumber.
At this time, I need to go to phpmyadmin, to have in a look in the categorytable.
Why not show that number on the b2categories.php page ?
It can't be that hard I think.
At this time, you can just look at the URL in the statusbar when you move the mouse pointer on a category link anywhere.
No need to go to the database.