I'm retrofitting a V9 site with a new 'sub site' This site will have it's own navigation system and IA. My plan, maybe, is to create a new folder in the content tree named 'New Site' and then created all my pages and items within there.
For the domain, i would then create a domain alias, and set the 'Default Alias path' to the 'New Site' folder.
This so far seems clear. Is it possible to have cross site contamination? Ideally, the old and new sites wouldn't mix under a single URL. I'm worried about navigation on the old site ('css list menu') picking up pages from the new site.
Had i know this was the plan, i would have created folders for each site to isolate, but moving to that structure may cause a lot of problems.