Hello Vincent,

You can't actually have the same alias because when you are accessing a URL, it doesn't follow the category hierarchy. What we have here is a customized routing behavior as we have created separate menu's for each of the category

I think the category alias should follow the hierarchy, it is not like post where post name shouldn't be duplicate. But in most of the cases category name definitely will be the same if our forums are focused on product related topics(like stackideas). This is not a pretty SEF link if the client are very specific on SEF link building, this just won't work and will create massive work load if the forums became bigger and bigger. (ie. installation-29) just doesn't look good, it look very unprofessional.

The Stackideas official forums give me a illusion that it is possible.

Traversing the "category tree" to get the url structure is actually heavy for your database Imagine if you have a pretty deep category tree, the URL wouldn't make sense either.

I had look into some other CMS / PHP code. ie wordpress
When the structure or name are the same, this is the method/algorithm for the alias/slug

Categories alias
YESlider (0) yeslider
Tutorials (1) tutorial
Beta (1) beta
Setup (1) setup

YEEditor (0) yeeditor
Tutorials (1) tutorial-yeeditor
Beta (1) beta-yeeditor
Setup (1) setup-yeeditor

It will make a NAME - PARENT_CAT_NAME - *NUMBER
* only appear when both parent category name are the same (rarely happen, but it may so for such case I am ok to add a number to it)
the number appear only if the 2 main categories name are duplicate like below scenario.

Categories alias
YESlider (0) yeslider
Tutorials (1) tutorial
Beta (1) beta
Setup (1) setup

YESlider (0) yeslider-1
Tutorials (1) tutorial-yeslider-1
Beta (1) beta-yeslider-1
Setup (1) setup-yeslider-1

Thanks for the heads up on this. I will try to see if there's any way to see if there's a way to update this in the next release. I guess the biggest issue / hurdles that we have is when users wants short URLs without the category structure in the URL.