Using WordPress ‘add_shortcode()’ PHP function
The `add_shortcode()` function in WordPress allows developers to create their own custom shortcodes using a callable function and optional attributes
CASE
Using WordPress ‘add_image_size()’ PHP function
The `add_image_size()` function in WordPress allows developers to register a new image size with custom dimensions and cropping behavior
Using WordPress ‘comment_author_url_link()’ PHP function
Displays the HTML link of the URL of the author of the current comment.
Using WordPress ‘avoid_blog_page_permalink_collision()’ PHP function
Avoids a collision between a site slug and a permalink slug.