This website blocks any comments it considers to be spam. The following criteria are used to determine what is a legitimate comment:

Trust approved commenters – authors who have previously commented and are known by a valid email address
BBCode verification – Comments with Bulletin Board Code (BBCode) in the content are clearly spam. The site and blog have not been configured to allow commentators to use bulletin board code.
Regular Expressions – There are spam comments that correspond to a specific pattern. For this purpose, predefined regular expressions are used for attributes of a WordPress comment (comment text, e-mail address, link, and IP). The search is intended to recognize clear contexts and classify spam.
Local Spam database comparison – A comparison of the URL, IP and email addresses of posted comments with locally available values of spam-marked comments – which are in the blog database. In plaintext: If the blog already contains a spam entry with an identical IP, URL or e-mail address, this attempt to comment is classified as a pest and treated accordingly (marked or deleted) depending on the settings.
English only comments – Comments are only allowed in English.

Restriction: Only for comments