Hi Dirk,
I do not won't this pages to be accessible since then we will have lots of duplicate content.
Before i added canonical tags to all the category pages, lots of them where indexed by google (i have no clue way). Therefor we added the canonical.
What do you think of the following:
On all filtered pages have canonical tags to the main category page (the first one)
and category pages without filters have rel = “next/prev”.
what do you think?
Thanks,
Yehoshua