register_post_meta()

register_post_meta() — Registers a meta key for posts.

Inputs: $post_type (string): Post type to register a meta key for. Pass an empty string to register the meta key across all existing post types. $meta_key (string): The meta key to register. $args (array): Data used to describe the meta key when registered. See register_meta() for a list of supported arguments.

Returns bool: True if the meta key was successfully registered, false if not.