Hello and thanks to all,

NeonKhnight, I didn'i realize that layer was a property of an object. It helps me a lot!
In fact there is a lot of thing that are properties in CC3, it changes me from others tools. I'll explore more others properties.

mattcolville, I've try you'r advice, but still I have problem selecting some objects. I thing that it is more linked to the nature of it than to the manipulations themselves. Bitmap objects have a invisible boundary that is not obvious to select and that overlap a lot around the picture itself (i.e.: beautiful bitmap mountains in SS1e catalog).
No reel problem with the standard ones for exemple.

Another question, just to but sure: for the problem of not viewing STRUCTURES and VEGETATION layers if I don't make the layer SYMBOL DEFINITION visible, I have deduced that it is some "special layer" that contain all the symbol definition (others identical symbol used are just some copies, as indicate in the manual). I found the confirmation in the help. So, I believe there is some few "special" layer, as the SYMBOL DEFINITION and MERGE, but I didn't find a list of these and what are their reel function. I appreciate explanations, and also where to find it in help or manual.

Thanks.

Q'Xel

P.S.: for the little story, I purchased CC3 (and SS1 extention) to make maps for Dominions 3. So, this is not just an artistic creation, but I have some others constraints for the intendend use in the game (such as visibility, help for editing provinces afterward, etc.). I'm working right now on my first map. I'll post it here for critics and comments, if you permit of course.