Documentation How to make terms and taxonomies not global on WordPress.com

How to make terms and taxonomies not global on WordPress.com

By default WordPress.com uses a little known (and now off by default) feature of WordPress Multisite called Globalized terms.  This means that terms are shared across sites. To remove your taxonomy from the global taxonomy array you can use the wpcom_is_globalized_taxonomy filter. This filter has 2 parameters $is_globalized and $taxonomy_name.