CD - Unique ID

Is there any kind of unique ID on a CD. I have a whole box of CD’s from a client and most of them have the name, “Untitled”. I am copying the images from the CD’s to a server and creating a database. I’m not sure that I will need it, but if there is some type of unique ID embedded on the CD’s, I’d like to capture it. I’m still having trouble getting over the idea that someone would create 50 CD’s all with the name “Untitled”