This WordPress snippet will let you show a list of post by a specific user. This is useful if you for example want to show post from a specific user on Custom Post Types etc.
Here is a snippet that enables you to restrict certain usernames from being created by new users registering to your WordPress website.
Heres a little trick on how to add custom WordPress user profile fields
With this snippet you can create a page template restricted only to those users with the right role to access to it.
This snippet will help you to redirect a WordPress user after login, based on the user role.