Create Private Courses Hidden from Public?

Is it possible to have a course that is available, but not publicly listed on the site? - i.e. you can provide students with access to it, but not display it as being available to enroll in? I am also wanting to have courses that are publicly available for students to enroll in as well.

Currently I have these courses set to free and available for anyone with the access code, however I do not want them to display to the public, so I would like to be able to email out an invitation to certain people to be able to join - how can you give students access and have a course not set to active/published?

I just tested giving myself access to an unpublished course through the email invitation, but the links in the email don't work.

Thank-you.