You didn't make it clear in your original post "what" didn't deal well with commas, and making it following my post where I mentioned the feature in the Quality Check plugin made it look like there was an issue in that, which there is not as far as I know.
So it seems in fact you were responding to chaley's comment about the Edit Metadata screen? And that too works perfectly fine for me for your example given. I suspect you haven't set your author sort tweak properly for the behaviour you are trying to achieve, mine is set to "copy" and has no issues with using those functions, no sign of a trailing comma.
|