PDF Placeholder for Calibre's Publisher Field

Greetings,

Does anyone know what field has to be filled out in the document properties of a PDF so that when imported into Calibre the publisher information is already in place?

I can get the Author, Title of the Book, and Tags to come in; but having no sucess with what field in a PDF will port over the information Calbire needs to fill in the Publisher metadata.

Thanks!
Tom