WordPress doesn’t allow you to use register_taxonomy multiple times to add the same taxonomy type to more than 1 custom post type. If you try and do it that way, your custom taxonomy types will not display. At least they didn’t when i tested in Genesis.
In this example, we’re adding countries and regions to custom post types golf courses and golf resorts.
Here’s the code for Genesis users which enables you to add the same taxonomy to more than 1 custom post type. Included is the code which also creates both CPT’s used to test the code so all you may need to do is swap out all instances of the CPT & taxonomy names with your own.
Click here to get full access to this tutorial & other theme specific tutorials like it.