Category pages should enable to use and switch filters which would filter the displayed content (and to set some other display parameters). Some ideas:
- filter by type of content (only categories, only pages, only files, only jpg files...)
- filter by date of creation/upload: (only new pages, pages created between 2010-2011, pages created before 2000 etc.)
- filter by date of last modification (can enable to pick "live" or "dead" articles)
- filter by count of edits/changes/reuploads (can enable to reflect importancy and attractiveness of the content)
- filter by size/length
- display only pages from my watchlist/only unwatched pages
- filter by tags (only featured articles/images, only stubs, only articles with NPOV warning, only images/articles with/without geocoordinates, only hidden categories, only redirects...)
- filter by concourse of categories (display only content which is simultaneously in Category:B) (Cat-a-lot can be improved to utilize it)
- a related feature can be to enable to display content of subcategories (of 1 level, 2 levels, all levels) directly in the current category as required in bug 43424.
- set (change) the number of displayed categories/pages/images (in total and on the page)
- set (change) the sorting of the content - (not only by alphabet but optionally by size, by date of creation/upload, by date of last modification etc.)
Of course, the conditions should be combinable and it should be possible to save the filter combinations and possibly also to share them (the most useful filters should be predefined and defaultly offered).