Some sites have areas you don't want to appear on the map or take a long time to scan (e.g. forum postings)

You can prevent these being scanned using the Links tab in the Options window (you get to this using the Options... command on the View menu).

You can block specific pages or use wildcards to block folders or specific file types. For example:

"http://www.domain.com/privacy.htm"
- just block this page

"http://www.domain.com/forum*"
- block the forum folder

"*.pdf"
- block all PDFs

Note: quotes are only used to make the examples clearer.