HelgaTheViking

Replace the default taxonomy boxes with a custom metabox that uses radio buttons… effectively limiting each post to a single term in that taxonomy.
A plugin options page allows the user can select which taxonomies she’d like to switch to using the custom radio-button style metabox.
Originally based on the the <a href="https://github.com/stephenh1988/Radio-Buttons-for-Taxonomies" rel="nofollow ugc">class by Stephen Harris</a>
<h4>Support</h4>
Support is handled in the <a href="https://wordpress.org/support/plugin/radio-buttons-for-taxonomies" rel="ugc">WordPress forums</a>. Please note that support is limited and does not cover any custom implementation of the plugin. Before posting a question, read the <a href="https://wordpress.org/plugins/radio-buttons-for-taxonomies/#faq" rel="ugc">FAQ</a> and confirm that the problem still exists with a default theme and with all other plugins disabled.
Please report any bugs, errors, warnings, code problems to <a href="https://github.com/helgatheviking/Radio-Buttons-for-Taxonomies/issues" rel="nofollow ugc">Github</a>

Radio Buttons for Taxonomies

Thank you so much for this plugin, so easy to use and makes creating a single category situations much easier.

Oh this is a life saver!

JUST WORKS

Many thanks to the author for this great plugin. Does one things and does it very well. Works with classic editor and block editor.

5 stars is not enough. Works with Gutenberg

We've been using this plugin for longer than we can remember, never had any issues whatsoever, highly recommended!

Excellent

Replace the default taxonomy boxes with a custom metabox that uses radio buttons... effectively limiting each post to a single term in that taxonomy.

wycks

For WordPress 3.8 and above, enhancements to the admin interface which retain most of the core aesthetics of 3.8. It makes the Admin easier to read, especially when you have a lot of menu items.
This admin interface is adjusted for great nation of better reading abilities.
<ul>
<li><a href="https://wordpress.org/plugins/better-admin-reading/screenshots/" rel="ugc">Screenshots</a>.</li>
<li><a href="https://twitter.com/wycks_s/status/415926766130036736" rel="nofollow ugc">Screenshot when used with the admin-color-schemer plugin</a>.</li>
</ul>
Please create any issues or requests on <a href="https://github.com/wycks/WP-Better-Admin-Reading" rel="nofollow ugc">GitHub</a>
Notes:
<ul>
<li>Loads a simple admin only CSS file and adjusts the padding, font-size and seperation of menu items, it also adjusts a few other minor things.</li>
<li>Works with the new admin color schemes, you must hit save after choosing the color theme for the CSS to be applied. This is found under your user settings.</li>
<li>Makes the font smaller for tablets and mobile.</li>
<li>Works with <a href="https://wordpress.org/plugins/admin-color-schemer/" rel="ugc">Admin color schemer</a></li>
</ul>
Some of the CSS code was forked from Admin Interface by Avenue Factory

Better Admin Reading

Restores balance to WordPress 3.8's admin. Improves the admin experience especially if you have a lot of menu items.

Radio Buttons for Taxonomies vs Better Admin Reading