Scott Reilly

This plugin allows you to restrict the usernames that new users may use when registering for your site.
If open registration is enabled for your site (via Settings -> General -> Membership (“Anyone can register”)), WordPress allows visitors to register for an account on your blog. By default, any username they choose is allowed so long as it isn’t an already existing account and it doesn’t include invalid (i.e. non-alphanumeric) characters.
Possible reasons for wanting to restrict certain usernames:
<ul>
<li>Prevent usernames that contain foul, offensive, or otherwise undesired words</li>
<li>Prevent squatting on usernames that you may want to use in the future (but don’t want to actually create the account for just yet) (essentially placing a hold on the username)</li>
<li>Prevent official-sounding usernames from being used (i.e. help, support, pr, info, sales)</li>
<li>Prevent official username syntax from being used (i.e. if all of your administrators use a prefix to identify themselves, you don’t want a visitor to use that prefix)</li>
<li>Prevent spaces from being used in a username (which WordPress allows by default)</li>
<li>Require that a username starts with, ends with, or contain one of a set of substrings (i.e. “support_”, “admin_”)</li>
<li>Require a minimum number of characters for usernames</li>
<li>Limit usernames to a maximum number of characters</li>
</ul>
When attempting to register with a restricted username, the visitor will be given an error notice that says: 
ERROR: This username is invalid. Please enter a valid username.
NOTE: This plugin does not put any restrictions on usernames that the admin chooses for users when creating user accounts from within the WordPress admin. This only restricts the names that users choose themselves when registering for your site.
SPECIAL NOTE: Many membership plugins implement their own user registration handling that often bypasses checks (and hooks) performed by WordPress. As such, it is unlikely that the plugin is compatible with them without special plugin-specific amendments.
Compatible with Multisite and BuddyPress as well.
Links: <a href="http://coffee2code.com/wp-plugins/restrict-usernames/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/restrict-usernames/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffee2code/restrict-usernames/" rel="nofollow ugc">GitHub</a> | <a href="http://coffee2code.com" rel="nofollow ugc">Author Homepage</a>
<h3>Hooks</h3>
The plugin exposes one filter for hooking. Typically, customizations utilizing this hook would be put into your active theme’s functions.php file, or used by another plugin.
c2c_restrict_usernames-validate (filter)
The ‘c2c_restrict_usernames-validate’ hook allows you to add your own customized checks for the username being registered. You can add additional restrictions or override the assessment performed by the plugin.
Arguments:
<ul>
<li>$valid (boolean): The assessment by the plugin about the validity of the username based on settings. True means username can be used.</li>
<li>$username (string): The username being registered.</li>
<li>$settings (array): The plugin’s settings.</li>
</ul>
Example:
<pre><code>/**
 * Add custom checks on usernames.
 *
 * Specifically, prevent use of usernames ending in numbers.
 *
 * @param bool $valid True if the username is valid, false if not.
 * @param string $username The username.
 * @param array $options Plugin options.
 */
function my_restrict_usernames_check( $valid, $username, $options ) {
 // Only do additional checking if the plugin has already performed its
 // checks and deemed the username valid.
 if ( $valid ) {
 // Don't allow usernames to end in numbers.
 if ( preg_match( '/[0-9]+$/', $username ) ) {
 $valid = false;
 }
 }
 return $valid;
}
add_filter( 'c2c_restrict_usernames-validate', 'my_restrict_usernames_check', 10, 3 );
</code></pre>

Restrict Usernames

Restrict the usernames that new users may use when registering for your site.

runthings.dev

Category Children Coupons for WooCommerce provides a complete replacement for WooCommerce’s built-in coupon category restrictions with additional flexibility:
Include children mode: Select a parent category and all its subcategories are automatically included. With WooCommerce’s default restrictions, selecting “Clothing” only matches products directly in that category – not products in “T-Shirts” or “Trousers” subcategories. This plugin includes the entire category tree.
Exclude children mode: Match only the specific categories you select, without including subcategories. This mirrors WooCommerce’s built-in behavior but is managed within this plugin’s unified interface.
Future-proof coupons: The plugin stores your category selection and dynamically expands child categories at validation time – new subcategories are automatically included (or excluded) without editing existing coupons.
<h4>Features</h4>
<ul>
<li>Four category restriction fields for complete control:
<ul>
<li>Product categories (incl. children) – allowed categories with all descendants</li>
<li>Exclude categories (incl. children) – blocked categories with all descendants</li>
<li>Product categories (excl. children) – allowed categories only, no descendants</li>
<li>Exclude categories (excl. children) – blocked categories only, no descendants</li>
</ul>
</li>
<li>Automatic subcategory handling based on your preference</li>
<li>Works alongside WooCommerce’s other (non-category coupon) restrictions</li>
<li>Customizable error messages via filter</li>
<li>AutomateWoo compatibility – category restrictions are copied when generating coupons from templates</li>
</ul>
<h4>How It Works</h4>
When you select a category in an “(incl. children)” field, the plugin automatically includes all subcategories during validation. When you use an “(excl. children)” field, only the exact categories you select are matched. Selected categories with children included are validated at usage time, so the current children are automatically used, even if they have changed since the coupon was set up.
<h3>Filters</h3>
<h4>runthings_category_children_coupons_error_message</h4>
Customize the error message shown when a coupon fails category validation.
Parameters:
<ul>
<li><code>$message</code> (string) – The default error message.</li>
<li><code>$context</code> (array) – Contains ‘coupon’ (WC_Coupon object) and ‘type’ (‘allowed’, ‘excluded’, ‘allowed_excl’, or ‘excluded_excl’).</li>
</ul>
Example:
See <a href="https://github.com/runthings-dev/runthings-category-children-coupons#filters" rel="nofollow ugc">readme.md on GitHub</a> for detailed code examples.
<h3>Additional Notes</h3>
Built by Matthew Harris of runthings.dev, copyright 2025.
Visit <a href="https://runthings.dev/" rel="nofollow ugc">runthings.dev</a> for more WordPress plugins and resources.
Contribute or report issues at the <a href="https://github.com/runthings-dev/runthings-category-children-coupons" rel="nofollow ugc">GitHub repository</a>.
Icon – Discount by Gregor Cresnar, from Noun Project, https://thenounproject.com/browse/icons/term/discount/ (CC BY 3.0)
Icon – Tree view by Paweł Gleń from Noun Project, https://thenounproject.com/browse/icons/term/tree-view/ (CC BY 3.0) – https://thenounproject.com/icon/tree-view-3894745/

Category Children Coupons for WooCommerce

Restrict WooCommerce coupons by product categories, with options to include or exclude child/descendant categories.

Restrict Usernames vs Category Children Coupons for WooCommerce