This is a MySQL/MariaDB hint.

It's useful because it instructs MySQL or MariaDB to place a limit on long SQL queries, typical in lists of items like categories, tags, search results etc.

Such lists (= the itemlist view in K2) can be abused by crawlers, bad actors etc., so it's a nice way to protect the health of your database. How do we know? Well, only because the highest traffic sites in the world are built with K2 and NOT Joomla's com_content.

And this is reason #385739485 why K2 kicks ass compared to poor old Joomla, whose trajectory is that of a falling satellite (hint: will it crash or burn first?).

We got big plans for 2024 for K2 but my mouth is sealed ;)