[AndrewD]

Originally Posted by Nam

I found out that I was able to select one link to be listed in multiple category (hold Ctrl and select files), but I was unable to select one sub-category to be listed in multiple category, or is it?

For example:

- Category A
-- B
-- C
- Category D
-- E

Could I make C belong to both A and D? So when people click on A and C, they will all see the same C. Save me tons of time by creating another sub-category C in main D.

No, this is not possible, and it was an important design decision to prevent problems. The categories create what is usually called a 'tree structure'. The important feature is that you can walk along a tree structure and know that you will eventually reach the beginning/end. If you allow a category to be a subcategory of more than one other category, that no longer applies. It's possible to create 'loops', so the coding becomes harder and more complicated to avoid getting stuck/produce sensible layouts/menus/etc.

However, you can achieve the same (similar) result by creating an entry which are actually pointers to your categories (i.e. make the url /local_links.php?catid=NN), and put this entry in multiple categories. If you give it a display order of 0, you can also ensure it appears at the top of the list with a separator.