Create a separate Publisher field.

[rosiel]

From the Metadata Interest Group:

Publisher information is usually considered different from other contributor fields, so it does not make a great deal of sense to lump publishers in with the creators and contributors of an object. For one thing, it makes it very hard to do a fielded search on publisher (or search for authors without including publishers.

Furthermore, per metadata guidelines such as RDA and AACR2, the names of publishers are entered directly, based on what's on the item (i.e. not controlled), and sometimes abbreviated. This diversity of names makes it a bad candidate for using a taxonomy term for publisher.

We therefore propose pulling Publisher out into its own field (text field).