Mark Jaquith

<ol>
<li>Check a category.</li>
<li>Uncheck “Uncategorized”.</li>
<li>Mutter “stupid ‘Uncategorized'” under your breath.</li>
</ol>
Sound familiar? With this stupidly simple plugin, you just have to do the first step. When you check a category and the default category was the only thing checked before you clicked, it’ll uncheck the default category for you. Boom.

Categorized

Unchecks the default post category when you first select a non-default category

Andrea Landonio

Taxonomy Filter is a simple and flexible plugin which allow users to filter hierarchical term taxonomies inside admin pages. If you need to simplify your tags and categories research on admin pages, this plugin will make it easier for you. It adds a custom input field (only for configured taxonomies) that you can use to filter a every taxonomy list.
Imagine having too many tags on your post admin page and having to lose so much time scrolling a long list of items or having to search for a tag with the classic browser search box. With “Taxonomy Filter” plugin you can search, choice and select tags in a very short time, a great gain!
In addition, you have to setup which taxonomies should have “Taxonomy Filter” activated. When you install and activate the plugin, an admin page is added on settings section. In this page are automatically listed all valid taxonomies, you have two options:
<ul>
<li>enable on post management pages (allow you to turn on/off filter field)</li>
<li>hide filter field if taxonomy is empty</li>
</ul>
You can also manage taxonomy filters into bulk edit section if you want to perform a quick edit.
If in your theme you have changed post columns using the ‘manage_edit-post_columns’ filter, you need to add another filter to apply the taxonomy filter bulk section. 
For example:
<pre><code>add_filter('manage_edit-post_columns', 'taxonomy_filter_manage_bulk_columns', 99, 1);
add_filter('manage_edit-<CUSTOM-TYPES>_columns', 'taxonomy_filter_manage_bulk_columns', 99, 1);
</code></pre>
It works only with hierarchical taxonomies (both default categories and <a href="https://codex.wordpress.org/Custom_Taxonomies" rel="nofollow ugc">custom taxonomies</a>).
When you enable a taxonomy filter, a section for choosing hidden taxonomy terms is displayed in user profile page and in term edit pages. In user profile page you can select (for each user) a list of taxonomy terms that are removed from hierarchical term taxonomies inside admin pages. 
By default, all taxonomy terms are visible in the hierarchical term taxonomies sections inside admin pages. You can choose only from max 2 nested levels but all the children of a hidden term are automatically removed from admin pages. Keep in mind that the hidden terms are not searchable and filterable. 
In edit term page you can select (for all users) if term should be removed (make hidden) from hierarchical term taxonomies inside admin pages.
<h4>Usage</h4>
<ol>
<li>Go to <code>WP-Admin -> Posts -> Add New</code>.</li>
<li>Find the input filter field on page sidebar.</li>
<li>Select tags filtering list.</li>
</ol>
Links: <a href="http://www.andrealandonio.it" rel="nofollow ugc">Author’s Site</a>

Taxonomy Filter

Taxonomy Filter is a plugin which allow users to filter hierarchical taxonomy terms inside admin pages and provides a way to hide terms for each user

Categorized vs Taxonomy Filter