In this chapter, we saw how to take Discretionary Access Control to the proverbial next level. We first saw how to create and manage access control lists to provide more fine-grained access control over files and directories. We then saw how to create a user group for a specific purpose, and how to add members to it. Then, we saw how we can use the SGID bit, the sticky bit, and access control lists to manage a shared group directory. 

But, sometimes, Discretionary Access Control might not be enough to do the job. For those times, we also have mandatory access control, which we'll cover in the next chapter. I'll see you there.