Discussion Forum—A Way with Words, a fun radio show and podcast about language

Someone recently questioned the use of "ISBN number" at work. While it's a great example of RAS syndrome (Redundant Acronym Syndrome syndrome), I have a vague memory of a recent podcast where Martha and Grant discussed this and maybe even sanctioned it. I want to listen to it again so I can reference it to my co-worker--but which podcast was it? Or am I just misremembering? (BTW, I love that each subject is listed with the podcasts now to make things generally easier to find!)