"Obi" is a Japanese word for the sash (cloth belt) worn with kimonos. From what I read somewhere a while ago, it's also used as a decorative band around an LP (aka vinyl disc). Unless you're some collector of CDs and the things that go with them (i.e. booklets, etc), I don't think it matters whether you keep it or not, but it'd be up to you to decide that
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