Lock categories, tags, and other taxonomy terms.

WP Term Locks allows administrators to lock taxonomy terms from being edited or deleted, providing security from authors & contributors that may try to modify them.

• Download and install using the built in WordPress plugin installer.
• Activate in the "Plugins" area of your admin by clicking the "Activate" link.
• No further setup or configuration is necessary.

Not since WordPress 4.4.

Install the WP Term Meta plugin if you're on an earlier version.

No. There are no new database tables with this plugin.

No. All of WordPress's core database tables remain untouched.

Yes. Use a meta_query like:

$terms = get_terms( 'category', array(
	'depth'      => 1,
	'number'     => 100,
	'parent'     => 0,
	'hide_empty' => false,

	// Query by lock using the "wp-term-meta" plugin!
	'meta_query' => array( array(
		'key' => 'locks'
	) )
) );

The WordPress support forums: https://wordpress.org/support/plugin/wp-term-locks/

Yes, please! The number of users needing more robust taxonomy visuals is growing fast. Having an easy-to-use UI and powerful set of functions is critical to managing complex WordPress installations. If this is your thing, please help us out!