Can I make images posted by users NOT SHOW on "Random Images" or "Recent Images"? And also, can I direct that they post to a particular category only? TIA.
You can set which usergroups can post to each categories of photos sure by setting permissions inder admin => edit categiries
As far as making images posted by users not show on photo blocks I am not following what your asking. There would most likely not be any switch for what you want but your free to modify the code in any manner you need to.
Linear Mode
