about oreos.
I attended a yu presentation about two years ago.
they said that (as of that time)
there were no dairy ingredients or dairy problems with oreos
in any of the many plants where they are manufactured.
but.
Nabisco refuses a pareve designation because they reserve the right to begin using a dairy ingredients (or non-pareve certified ingredients ) or dairy equipment at any time.
IOW. Oreos were completely pareve then, but may not be today and may not be tomorrow.
I suspect by some arrangement they (the ou and nabisco) allowed that run for the crumbs to be marked pareve.