I found out by myself.
Go to manage extensions and edit the "content" extension. In common tab, set "Add menu title to URL" to "No". You will get the default joomla URL scheme.
That's so complicated... Why is this option set to "Yes" by default ?
In addition, I will recomend to go in "Extension tab" and set :
- "add layout to URL" to "Never"
- "Default Layout" to "blog
Otherwise, all category blog URLs will have the word "blog" at the end of their URL.
There are a lot of little text mistakes like the info bubble "How to handle the layout fieldeter" of the "Add layout to URL option". If "fieldeter" is a real word what does it mean ?
I think there's a lot of things which could be changed by default. It will avoid people wasting time with a product they paid for...