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.

WPClever

The WPC Checkout Restrictions plugin for WooCommerce is a powerful tool that empowers store owners to customize and control the checkout process with precision. This plugin allows you to set specific restrictions based on a variety of conditions, ensuring that only eligible customers can complete their purchases.
<h4>Key Features</h4>
<ul>
<li>User Role Restrictions: Limit checkout to specific user roles, giving you the ability to restrict purchases to authorized customers only.</li>
<li>Cart Content Restrictions: Define rules such as minimum or maximum cart totals required for checkout, or block checkout if certain products are present in the cart.</li>
<li>Advanced Time Restrictions: Implement sophisticated time-based rules to control checkout availability. Set multiple conditions such as specific time windows, recurring schedules, or exceptions for holidays, ensuring your store’s checkout process aligns perfectly with your operational needs.</li>
<li>Custom Messages: Display personalized messages to inform customers about the restrictions and provide clear guidance on how to meet the checkout requirements.</li>
</ul>
<h4>Why Use It?</h4>
This plugin is an excellent solution for managing promotions, controlling checkout availability, or enforcing specific purchase conditions. Whether you’re running a time-sensitive offer, restricting access to exclusive products during certain hours, or ensuring compliance with your store’s operational schedule, WPC Checkout Restrictions offers the flexibility you need.
<h4>Compatibility & Reception</h4>
Fully compatible with the latest versions of WordPress and WooCommerce, the plugin has earned positive feedback from users for its effectiveness and ease of use. It’s a reliable choice for store owners looking to enhance control over their checkout experience.
With WPC Checkout Restrictions, you can streamline your store’s operations and create a tailored shopping experience that meets your business goals.
<h4>Need more features?</h4>
Please try other plugins from us:
<ul>
<li><a href="https://wordpress.org/plugins/woo-fly-cart/" title="WPC Fly Cart" rel="ugc">WPC Fly Cart</a></li>
<li><a href="https://wordpress.org/plugins/wpc-ajax-add-to-cart/" title="WPC AJAX Add to Cart" rel="ugc">WPC AJAX Add to Cart</a></li>
<li><a href="https://wordpress.org/plugins/wpc-free-shipping-bar/" title="WPC Free Shipping Bar" rel="ugc">WPC Free Shipping Bar</a></li>
<li><a href="https://wordpress.org/plugins/wpc-smart-linked-products/" title="WPC Smart Linked Products" rel="ugc">WPC Smart Linked Products</a></li>
<li><a href="https://wordpress.org/plugins/wpc-smart-upsell-funnel/" title="WPC Smart Upsell Funnel" rel="ugc">WPC Smart Upsell Funnel</a></li>
</ul>

WPC Checkout Restrictions for WooCommerce

Enables merchants to quickly set checkout restrictions based on user roles, cart totals, item quantities, time, and products in the cart.

Restrict Usernames vs WPC Checkout Restrictions for WooCommerce