WordPress 5.1 will feature a new parameter for register_taxonomy(), ‘meta_box_sanitize_cb’, which increases flexibility when using core UI for custom taxonomies. Custom taxonomies can specify which metabox UI they’d like to use in the Classic Editor by providing a meta_box_cb parameter when registering their taxonomies. This meant, for example, that a hierarchical taxonomy can choose to … Continue reading Improved taxonomy metabox sanitization in 5.1