I know you can prevent individual pages from being indexed by Google/SEs (with robots.txt, password protection, etc.), but is there a way besides passwording protecting to prevent an entire directory from being indexed?

I've noticed that often include directorys are named "_inc", and I'm wondering if the leading "_" prevents indexing, or if there are any other ways.

Thanks.

The same way that you do it with robots.txt files for files you can just place a directory name in there.

Great. Thanks.