> For the complete documentation index, see [llms.txt](https://docs.boldminded.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.boldminded.com/advanced-categories/docs/setup-and-configuration/hidden-config-options.md).

# Hidden Config Options

`$config['advanced_categories_nuclear'] = 'yes';`

Enabling this option will only save categories from Advanced Categories fields. This means if there is 1 Advanced Categories field, and 5 category groups assigned to an entry then any selected category in the native category field groups will be unselected unless it's selected in an Advanced Categories field on the entry.