Options Junk Files / Include page lists the folders whose file contents must always be completely included in the Disk Cleaner's search results as it is knowingly junk.
You can use the buttons under the list to add new folders, modify existing ones or delete them. The wild characters * and ? can be used to define a set of folder names. Please note that you don't have to delete a folder just to exclude it from the search list; instead, you can simply remove the check mark from the box next to it.